forked from cores/microwatt
Anton Blanchard
4 years ago
committed by
GitHub
commit
65fc34cf6e
Binary file not shown.
Binary file not shown.
@ -0,0 +1,111 @@
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//////////////////////////////////////////////////////////////////////
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||||
//// ////
|
||||
//// raminfr.v ////
|
||||
//// ////
|
||||
//// ////
|
||||
//// This file is part of the "UART 16550 compatible" project ////
|
||||
//// http://www.opencores.org/cores/uart16550/ ////
|
||||
//// ////
|
||||
//// Documentation related to this project: ////
|
||||
//// - http://www.opencores.org/cores/uart16550/ ////
|
||||
//// ////
|
||||
//// Projects compatibility: ////
|
||||
//// - WISHBONE ////
|
||||
//// RS232 Protocol ////
|
||||
//// 16550D uart (mostly supported) ////
|
||||
//// ////
|
||||
//// Overview (main Features): ////
|
||||
//// Inferrable Distributed RAM for FIFOs ////
|
||||
//// ////
|
||||
//// Known problems (limits): ////
|
||||
//// None . ////
|
||||
//// ////
|
||||
//// To Do: ////
|
||||
//// Nothing so far. ////
|
||||
//// ////
|
||||
//// Author(s): ////
|
||||
//// - gorban@opencores.org ////
|
||||
//// - Jacob Gorban ////
|
||||
//// ////
|
||||
//// Created: 2002/07/22 ////
|
||||
//// Last Updated: 2002/07/22 ////
|
||||
//// (See log for the revision history) ////
|
||||
//// ////
|
||||
//// ////
|
||||
//////////////////////////////////////////////////////////////////////
|
||||
//// ////
|
||||
//// Copyright (C) 2000, 2001 Authors ////
|
||||
//// ////
|
||||
//// This source file may be used and distributed without ////
|
||||
//// restriction provided that this copyright statement is not ////
|
||||
//// removed from the file and that any derivative work contains ////
|
||||
//// the original copyright notice and the associated disclaimer. ////
|
||||
//// ////
|
||||
//// This source file is free software; you can redistribute it ////
|
||||
//// and/or modify it under the terms of the GNU Lesser General ////
|
||||
//// Public License as published by the Free Software Foundation; ////
|
||||
//// either version 2.1 of the License, or (at your option) any ////
|
||||
//// later version. ////
|
||||
//// ////
|
||||
//// This source is distributed in the hope that it will be ////
|
||||
//// useful, but WITHOUT ANY WARRANTY; without even the implied ////
|
||||
//// warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR ////
|
||||
//// PURPOSE. See the GNU Lesser General Public License for more ////
|
||||
//// details. ////
|
||||
//// ////
|
||||
//// You should have received a copy of the GNU Lesser General ////
|
||||
//// Public License along with this source; if not, download it ////
|
||||
//// from http://www.opencores.org/lgpl.shtml ////
|
||||
//// ////
|
||||
//////////////////////////////////////////////////////////////////////
|
||||
//
|
||||
// CVS Revision History
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||||
//
|
||||
// $Log: not supported by cvs2svn $
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||||
// Revision 1.1 2002/07/22 23:02:23 gorban
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||||
// Bug Fixes:
|
||||
// * Possible loss of sync and bad reception of stop bit on slow baud rates fixed.
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||||
// Problem reported by Kenny.Tung.
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||||
// * Bad (or lack of ) loopback handling fixed. Reported by Cherry Withers.
|
||||
//
|
||||
// Improvements:
|
||||
// * Made FIFO's as general inferrable memory where possible.
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||||
// So on FPGA they should be inferred as RAM (Distributed RAM on Xilinx).
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||||
// This saves about 1/3 of the Slice count and reduces P&R and synthesis times.
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||||
//
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||||
// * Added optional baudrate output (baud_o).
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// This is identical to BAUDOUT* signal on 16550 chip.
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// It outputs 16xbit_clock_rate - the divided clock.
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// It's disabled by default. Define UART_HAS_BAUDRATE_OUTPUT to use.
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//
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//Following is the Verilog code for a dual-port RAM with asynchronous read.
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module raminfr
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(clk, we, a, dpra, di, dpo);
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parameter addr_width = 4;
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parameter data_width = 8;
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parameter depth = 16;
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input clk;
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input we;
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input [addr_width-1:0] a;
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input [addr_width-1:0] dpra;
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input [data_width-1:0] di;
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//output [data_width-1:0] spo;
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output [data_width-1:0] dpo;
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reg [data_width-1:0] ram [depth-1:0];
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wire [data_width-1:0] dpo;
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wire [data_width-1:0] di;
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wire [addr_width-1:0] a;
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wire [addr_width-1:0] dpra;
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always @(posedge clk) begin
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if (we)
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ram[a] <= di;
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end
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// assign spo = ram[a];
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assign dpo = ram[dpra];
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endmodule
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@ -0,0 +1,233 @@
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//////////////////////////////////////////////////////////////////////
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//// ////
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||||
//// uart_defines.v ////
|
||||
//// ////
|
||||
//// ////
|
||||
//// This file is part of the "UART 16550 compatible" project ////
|
||||
//// http://www.opencores.org/cores/uart16550/ ////
|
||||
//// ////
|
||||
//// Documentation related to this project: ////
|
||||
//// - http://www.opencores.org/cores/uart16550/ ////
|
||||
//// ////
|
||||
//// Projects compatibility: ////
|
||||
//// - WISHBONE ////
|
||||
//// RS232 Protocol ////
|
||||
//// 16550D uart (mostly supported) ////
|
||||
//// ////
|
||||
//// Overview (main Features): ////
|
||||
//// Defines of the Core ////
|
||||
//// ////
|
||||
//// Known problems (limits): ////
|
||||
//// None ////
|
||||
//// ////
|
||||
//// To Do: ////
|
||||
//// Nothing. ////
|
||||
//// ////
|
||||
//// Author(s): ////
|
||||
//// - gorban@opencores.org ////
|
||||
//// - Jacob Gorban ////
|
||||
//// - Igor Mohor (igorm@opencores.org) ////
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||||
//// ////
|
||||
//// Created: 2001/05/12 ////
|
||||
//// Last Updated: 2001/05/17 ////
|
||||
//// (See log for the revision history) ////
|
||||
//// ////
|
||||
//// ////
|
||||
//////////////////////////////////////////////////////////////////////
|
||||
//// ////
|
||||
//// Copyright (C) 2000, 2001 Authors ////
|
||||
//// ////
|
||||
//// This source file may be used and distributed without ////
|
||||
//// restriction provided that this copyright statement is not ////
|
||||
//// removed from the file and that any derivative work contains ////
|
||||
//// the original copyright notice and the associated disclaimer. ////
|
||||
//// ////
|
||||
//// This source file is free software; you can redistribute it ////
|
||||
//// and/or modify it under the terms of the GNU Lesser General ////
|
||||
//// Public License as published by the Free Software Foundation; ////
|
||||
//// either version 2.1 of the License, or (at your option) any ////
|
||||
//// later version. ////
|
||||
//// ////
|
||||
//// This source is distributed in the hope that it will be ////
|
||||
//// useful, but WITHOUT ANY WARRANTY; without even the implied ////
|
||||
//// warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR ////
|
||||
//// PURPOSE. See the GNU Lesser General Public License for more ////
|
||||
//// details. ////
|
||||
//// ////
|
||||
//// You should have received a copy of the GNU Lesser General ////
|
||||
//// Public License along with this source; if not, download it ////
|
||||
//// from http://www.opencores.org/lgpl.shtml ////
|
||||
//// ////
|
||||
//////////////////////////////////////////////////////////////////////
|
||||
//
|
||||
// CVS Revision History
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||||
//
|
||||
// $Log: not supported by cvs2svn $
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||||
// Revision 1.13 2003/06/11 16:37:47 gorban
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// This fixes errors in some cases when data is being read and put to the FIFO at the same time. Patch is submitted by Scott Furman. Update is very recommended.
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//
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// Revision 1.12 2002/07/22 23:02:23 gorban
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// Bug Fixes:
|
||||
// * Possible loss of sync and bad reception of stop bit on slow baud rates fixed.
|
||||
// Problem reported by Kenny.Tung.
|
||||
// * Bad (or lack of ) loopback handling fixed. Reported by Cherry Withers.
|
||||
//
|
||||
// Improvements:
|
||||
// * Made FIFO's as general inferrable memory where possible.
|
||||
// So on FPGA they should be inferred as RAM (Distributed RAM on Xilinx).
|
||||
// This saves about 1/3 of the Slice count and reduces P&R and synthesis times.
|
||||
//
|
||||
// * Added optional baudrate output (baud_o).
|
||||
// This is identical to BAUDOUT* signal on 16550 chip.
|
||||
// It outputs 16xbit_clock_rate - the divided clock.
|
||||
// It's disabled by default. Define UART_HAS_BAUDRATE_OUTPUT to use.
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//
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// Revision 1.10 2001/12/11 08:55:40 mohor
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// Scratch register define added.
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//
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// Revision 1.9 2001/12/03 21:44:29 gorban
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// Updated specification documentation.
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// Added full 32-bit data bus interface, now as default.
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// Address is 5-bit wide in 32-bit data bus mode.
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// Added wb_sel_i input to the core. It's used in the 32-bit mode.
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// Added debug interface with two 32-bit read-only registers in 32-bit mode.
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// Bits 5 and 6 of LSR are now only cleared on TX FIFO write.
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// My small test bench is modified to work with 32-bit mode.
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//
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// Revision 1.8 2001/11/26 21:38:54 gorban
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// Lots of fixes:
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// Break condition wasn't handled correctly at all.
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// LSR bits could lose their values.
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// LSR value after reset was wrong.
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// Timing of THRE interrupt signal corrected.
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// LSR bit 0 timing corrected.
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//
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// Revision 1.7 2001/08/24 21:01:12 mohor
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// Things connected to parity changed.
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// Clock devider changed.
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//
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// Revision 1.6 2001/08/23 16:05:05 mohor
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// Stop bit bug fixed.
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// Parity bug fixed.
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// WISHBONE read cycle bug fixed,
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// OE indicator (Overrun Error) bug fixed.
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||||
// PE indicator (Parity Error) bug fixed.
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// Register read bug fixed.
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//
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// Revision 1.5 2001/05/31 20:08:01 gorban
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// FIFO changes and other corrections.
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//
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||||
// Revision 1.4 2001/05/21 19:12:02 gorban
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// Corrected some Linter messages.
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//
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// Revision 1.3 2001/05/17 18:34:18 gorban
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// First 'stable' release. Should be sythesizable now. Also added new header.
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//
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// Revision 1.0 2001-05-17 21:27:11+02 jacob
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// Initial revision
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//
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||||
//
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||||
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||||
// Uncomment this if you want your UART to have
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// 16xBaudrate output port.
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// If defined, the enable signal will be used to drive baudrate_o signal
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// It's frequency is 16xbaudrate
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||||
// `define UART_HAS_BAUDRATE_OUTPUT
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||||
// Register addresses
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||||
`define UART_REG_RB 3'd0 // receiver buffer
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||||
`define UART_REG_TR 3'd0 // transmitter
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||||
`define UART_REG_IE 3'd1 // Interrupt enable
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`define UART_REG_II 3'd2 // Interrupt identification
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`define UART_REG_FC 3'd2 // FIFO control
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`define UART_REG_LC 3'd3 // Line Control
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`define UART_REG_MC 3'd4 // Modem control
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`define UART_REG_LS 3'd5 // Line status
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||||
`define UART_REG_MS 3'd6 // Modem status
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||||
`define UART_REG_SR 3'd7 // Scratch register
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`define UART_REG_DL1 3'd0 // Divisor latch bytes (1-2)
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||||
`define UART_REG_DL2 3'd1
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||||
|
||||
// Interrupt Enable register bits
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||||
`define UART_IE_RDA 0 // Received Data available interrupt
|
||||
`define UART_IE_THRE 1 // Transmitter Holding Register empty interrupt
|
||||
`define UART_IE_RLS 2 // Receiver Line Status Interrupt
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||||
`define UART_IE_MS 3 // Modem Status Interrupt
|
||||
|
||||
// Interrupt Identification register bits
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||||
`define UART_II_IP 0 // Interrupt pending when 0
|
||||
`define UART_II_II 3:1 // Interrupt identification
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||||
|
||||
// Interrupt identification values for bits 3:1
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||||
`define UART_II_RLS 3'b011 // Receiver Line Status
|
||||
`define UART_II_RDA 3'b010 // Receiver Data available
|
||||
`define UART_II_TI 3'b110 // Timeout Indication
|
||||
`define UART_II_THRE 3'b001 // Transmitter Holding Register empty
|
||||
`define UART_II_MS 3'b000 // Modem Status
|
||||
|
||||
// FIFO Control Register bits
|
||||
`define UART_FC_TL 1:0 // Trigger level
|
||||
|
||||
// FIFO trigger level values
|
||||
`define UART_FC_1 2'b00
|
||||
`define UART_FC_4 2'b01
|
||||
`define UART_FC_8 2'b10
|
||||
`define UART_FC_14 2'b11
|
||||
|
||||
// Line Control register bits
|
||||
`define UART_LC_BITS 1:0 // bits in character
|
||||
`define UART_LC_SB 2 // stop bits
|
||||
`define UART_LC_PE 3 // parity enable
|
||||
`define UART_LC_EP 4 // even parity
|
||||
`define UART_LC_SP 5 // stick parity
|
||||
`define UART_LC_BC 6 // Break control
|
||||
`define UART_LC_DL 7 // Divisor Latch access bit
|
||||
|
||||
// Modem Control register bits
|
||||
`define UART_MC_DTR 0
|
||||
`define UART_MC_RTS 1
|
||||
`define UART_MC_OUT1 2
|
||||
`define UART_MC_OUT2 3
|
||||
`define UART_MC_LB 4 // Loopback mode
|
||||
|
||||
// Line Status Register bits
|
||||
`define UART_LS_DR 0 // Data ready
|
||||
`define UART_LS_OE 1 // Overrun Error
|
||||
`define UART_LS_PE 2 // Parity Error
|
||||
`define UART_LS_FE 3 // Framing Error
|
||||
`define UART_LS_BI 4 // Break interrupt
|
||||
`define UART_LS_TFE 5 // Transmit FIFO is empty
|
||||
`define UART_LS_TE 6 // Transmitter Empty indicator
|
||||
`define UART_LS_EI 7 // Error indicator
|
||||
|
||||
// Modem Status Register bits
|
||||
`define UART_MS_DCTS 0 // Delta signals
|
||||
`define UART_MS_DDSR 1
|
||||
`define UART_MS_TERI 2
|
||||
`define UART_MS_DDCD 3
|
||||
`define UART_MS_CCTS 4 // Complement signals
|
||||
`define UART_MS_CDSR 5
|
||||
`define UART_MS_CRI 6
|
||||
`define UART_MS_CDCD 7
|
||||
|
||||
// FIFO parameter defines
|
||||
|
||||
`define UART_FIFO_WIDTH 8
|
||||
`define UART_FIFO_DEPTH 16
|
||||
`define UART_FIFO_POINTER_W 4
|
||||
`define UART_FIFO_COUNTER_W 5
|
||||
// receiver fifo has width 11 because it has break, parity and framing error bits
|
||||
`define UART_FIFO_REC_WIDTH 11
|
||||
|
||||
|
||||
`define VERBOSE_WB 0 // All activity on the WISHBONE is recorded
|
||||
`define VERBOSE_LINE_STATUS 0 // Details about the lsr (line status register)
|
||||
`define FAST_TEST 1 // 64/1024 packets are sent
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
@ -0,0 +1,475 @@
|
||||
//////////////////////////////////////////////////////////////////////
|
||||
//// ////
|
||||
//// uart_receiver.v ////
|
||||
//// ////
|
||||
//// ////
|
||||
//// This file is part of the "UART 16550 compatible" project ////
|
||||
//// http://www.opencores.org/cores/uart16550/ ////
|
||||
//// ////
|
||||
//// Documentation related to this project: ////
|
||||
//// - http://www.opencores.org/cores/uart16550/ ////
|
||||
//// ////
|
||||
//// Projects compatibility: ////
|
||||
//// - WISHBONE ////
|
||||
//// RS232 Protocol ////
|
||||
//// 16550D uart (mostly supported) ////
|
||||
//// ////
|
||||
//// Overview (main Features): ////
|
||||
//// UART core receiver logic ////
|
||||
//// ////
|
||||
//// Known problems (limits): ////
|
||||
//// None known ////
|
||||
//// ////
|
||||
//// To Do: ////
|
||||
//// Thourough testing. ////
|
||||
//// ////
|
||||
//// Author(s): ////
|
||||
//// - gorban@opencores.org ////
|
||||
//// - Jacob Gorban ////
|
||||
//// - Igor Mohor (igorm@opencores.org) ////
|
||||
//// ////
|
||||
//// Created: 2001/05/12 ////
|
||||
//// Last Updated: 2001/05/17 ////
|
||||
//// (See log for the revision history) ////
|
||||
//// ////
|
||||
//// ////
|
||||
//////////////////////////////////////////////////////////////////////
|
||||
//// ////
|
||||
//// Copyright (C) 2000, 2001 Authors ////
|
||||
//// ////
|
||||
//// This source file may be used and distributed without ////
|
||||
//// restriction provided that this copyright statement is not ////
|
||||
//// removed from the file and that any derivative work contains ////
|
||||
//// the original copyright notice and the associated disclaimer. ////
|
||||
//// ////
|
||||
//// This source file is free software; you can redistribute it ////
|
||||
//// and/or modify it under the terms of the GNU Lesser General ////
|
||||
//// Public License as published by the Free Software Foundation; ////
|
||||
//// either version 2.1 of the License, or (at your option) any ////
|
||||
//// later version. ////
|
||||
//// ////
|
||||
//// This source is distributed in the hope that it will be ////
|
||||
//// useful, but WITHOUT ANY WARRANTY; without even the implied ////
|
||||
//// warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR ////
|
||||
//// PURPOSE. See the GNU Lesser General Public License for more ////
|
||||
//// details. ////
|
||||
//// ////
|
||||
//// You should have received a copy of the GNU Lesser General ////
|
||||
//// Public License along with this source; if not, download it ////
|
||||
//// from http://www.opencores.org/lgpl.shtml ////
|
||||
//// ////
|
||||
//////////////////////////////////////////////////////////////////////
|
||||
//
|
||||
// CVS Revision History
|
||||
//
|
||||
// $Log: not supported by cvs2svn $
|
||||
// Revision 1.29 2002/07/29 21:16:18 gorban
|
||||
// The uart_defines.v file is included again in sources.
|
||||
//
|
||||
// Revision 1.28 2002/07/22 23:02:23 gorban
|
||||
// Bug Fixes:
|
||||
// * Possible loss of sync and bad reception of stop bit on slow baud rates fixed.
|
||||
// Problem reported by Kenny.Tung.
|
||||
// * Bad (or lack of ) loopback handling fixed. Reported by Cherry Withers.
|
||||
//
|
||||
// Improvements:
|
||||
// * Made FIFO's as general inferrable memory where possible.
|
||||
// So on FPGA they should be inferred as RAM (Distributed RAM on Xilinx).
|
||||
// This saves about 1/3 of the Slice count and reduces P&R and synthesis times.
|
||||
//
|
||||
// * Added optional baudrate output (baud_o).
|
||||
// This is identical to BAUDOUT* signal on 16550 chip.
|
||||
// It outputs 16xbit_clock_rate - the divided clock.
|
||||
// It's disabled by default. Define UART_HAS_BAUDRATE_OUTPUT to use.
|
||||
//
|
||||
// Revision 1.27 2001/12/30 20:39:13 mohor
|
||||
// More than one character was stored in case of break. End of the break
|
||||
// was not detected correctly.
|
||||
//
|
||||
// Revision 1.26 2001/12/20 13:28:27 mohor
|
||||
// Missing declaration of rf_push_q fixed.
|
||||
//
|
||||
// Revision 1.25 2001/12/20 13:25:46 mohor
|
||||
// rx push changed to be only one cycle wide.
|
||||
//
|
||||
// Revision 1.24 2001/12/19 08:03:34 mohor
|
||||
// Warnings cleared.
|
||||
//
|
||||
// Revision 1.23 2001/12/19 07:33:54 mohor
|
||||
// Synplicity was having troubles with the comment.
|
||||
//
|
||||
// Revision 1.22 2001/12/17 14:46:48 mohor
|
||||
// overrun signal was moved to separate block because many sequential lsr
|
||||
// reads were preventing data from being written to rx fifo.
|
||||
// underrun signal was not used and was removed from the project.
|
||||
//
|
||||
// Revision 1.21 2001/12/13 10:31:16 mohor
|
||||
// timeout irq must be set regardless of the rda irq (rda irq does not reset the
|
||||
// timeout counter).
|
||||
//
|
||||
// Revision 1.20 2001/12/10 19:52:05 gorban
|
||||
// Igor fixed break condition bugs
|
||||
//
|
||||
// Revision 1.19 2001/12/06 14:51:04 gorban
|
||||
// Bug in LSR[0] is fixed.
|
||||
// All WISHBONE signals are now sampled, so another wait-state is introduced on all transfers.
|
||||
//
|
||||
// Revision 1.18 2001/12/03 21:44:29 gorban
|
||||
// Updated specification documentation.
|
||||
// Added full 32-bit data bus interface, now as default.
|
||||
// Address is 5-bit wide in 32-bit data bus mode.
|
||||
// Added wb_sel_i input to the core. It's used in the 32-bit mode.
|
||||
// Added debug interface with two 32-bit read-only registers in 32-bit mode.
|
||||
// Bits 5 and 6 of LSR are now only cleared on TX FIFO write.
|
||||
// My small test bench is modified to work with 32-bit mode.
|
||||
//
|
||||
// Revision 1.17 2001/11/28 19:36:39 gorban
|
||||
// Fixed: timeout and break didn't pay attention to current data format when counting time
|
||||
//
|
||||
// Revision 1.16 2001/11/27 22:17:09 gorban
|
||||
// Fixed bug that prevented synthesis in uart_receiver.v
|
||||
//
|
||||
// Revision 1.15 2001/11/26 21:38:54 gorban
|
||||
// Lots of fixes:
|
||||
// Break condition wasn't handled correctly at all.
|
||||
// LSR bits could lose their values.
|
||||
// LSR value after reset was wrong.
|
||||
// Timing of THRE interrupt signal corrected.
|
||||
// LSR bit 0 timing corrected.
|
||||
//
|
||||
// Revision 1.14 2001/11/10 12:43:21 gorban
|
||||
// Logic Synthesis bugs fixed. Some other minor changes
|
||||
//
|
||||
// Revision 1.13 2001/11/08 14:54:23 mohor
|
||||
// Comments in Slovene language deleted, few small fixes for better work of
|
||||
// old tools. IRQs need to be fix.
|
||||
//
|
||||
// Revision 1.12 2001/11/07 17:51:52 gorban
|
||||
// Heavily rewritten interrupt and LSR subsystems.
|
||||
// Many bugs hopefully squashed.
|
||||
//
|
||||
// Revision 1.11 2001/10/31 15:19:22 gorban
|
||||
// Fixes to break and timeout conditions
|
||||
//
|
||||
// Revision 1.10 2001/10/20 09:58:40 gorban
|
||||
// Small synopsis fixes
|
||||
//
|
||||
// Revision 1.9 2001/08/24 21:01:12 mohor
|
||||
// Things connected to parity changed.
|
||||
// Clock devider changed.
|
||||
//
|
||||
// Revision 1.8 2001/08/23 16:05:05 mohor
|
||||
// Stop bit bug fixed.
|
||||
// Parity bug fixed.
|
||||
// WISHBONE read cycle bug fixed,
|
||||
// OE indicator (Overrun Error) bug fixed.
|
||||
// PE indicator (Parity Error) bug fixed.
|
||||
// Register read bug fixed.
|
||||
//
|
||||
// Revision 1.6 2001/06/23 11:21:48 gorban
|
||||
// DL made 16-bit long. Fixed transmission/reception bugs.
|
||||
//
|
||||
// Revision 1.5 2001/06/02 14:28:14 gorban
|
||||
// Fixed receiver and transmitter. Major bug fixed.
|
||||
//
|
||||
// Revision 1.4 2001/05/31 20:08:01 gorban
|
||||
// FIFO changes and other corrections.
|
||||
//
|
||||
// Revision 1.3 2001/05/27 17:37:49 gorban
|
||||
// Fixed many bugs. Updated spec. Changed FIFO files structure. See CHANGES.txt file.
|
||||
//
|
||||
// Revision 1.2 2001/05/21 19:12:02 gorban
|
||||
// Corrected some Linter messages.
|
||||
//
|
||||
// Revision 1.1 2001/05/17 18:34:18 gorban
|
||||
// First 'stable' release. Should be sythesizable now. Also added new header.
|
||||
//
|
||||
// Revision 1.0 2001-05-17 21:27:11+02 jacob
|
||||
// Initial revision
|
||||
//
|
||||
//
|
||||
|
||||
`include "uart_defines.v"
|
||||
|
||||
module uart_receiver (clk, wb_rst_i, lcr, rf_pop, srx_pad_i, enable,
|
||||
counter_t, rf_count, rf_data_out, rf_error_bit, rf_overrun, rx_reset, lsr_mask, rstate, rf_push_pulse);
|
||||
|
||||
input clk;
|
||||
input wb_rst_i;
|
||||
input [7:0] lcr;
|
||||
input rf_pop;
|
||||
input srx_pad_i;
|
||||
input enable;
|
||||
input rx_reset;
|
||||
input lsr_mask;
|
||||
|
||||
output [9:0] counter_t;
|
||||
output [`UART_FIFO_COUNTER_W-1:0] rf_count;
|
||||
output [`UART_FIFO_REC_WIDTH-1:0] rf_data_out;
|
||||
output rf_overrun;
|
||||
output rf_error_bit;
|
||||
output [3:0] rstate;
|
||||
output rf_push_pulse;
|
||||
|
||||
reg [3:0] rstate;
|
||||
reg [3:0] rcounter16;
|
||||
reg [2:0] rbit_counter;
|
||||
reg [7:0] rshift; // receiver shift register
|
||||
reg rparity; // received parity
|
||||
reg rparity_error;
|
||||
reg rframing_error; // framing error flag
|
||||
reg rparity_xor;
|
||||
reg [7:0] counter_b; // counts the 0 (low) signals
|
||||
reg rf_push_q;
|
||||
|
||||
// RX FIFO signals
|
||||
reg [`UART_FIFO_REC_WIDTH-1:0] rf_data_in;
|
||||
wire [`UART_FIFO_REC_WIDTH-1:0] rf_data_out;
|
||||
wire rf_push_pulse;
|
||||
reg rf_push;
|
||||
wire rf_pop;
|
||||
wire rf_overrun;
|
||||
wire [`UART_FIFO_COUNTER_W-1:0] rf_count;
|
||||
wire rf_error_bit; // an error (parity or framing) is inside the fifo
|
||||
wire break_error = (counter_b == 0);
|
||||
|
||||
// RX FIFO instance
|
||||
uart_rfifo #(`UART_FIFO_REC_WIDTH) fifo_rx(
|
||||
.clk( clk ),
|
||||
.wb_rst_i( wb_rst_i ),
|
||||
.data_in( rf_data_in ),
|
||||
.data_out( rf_data_out ),
|
||||
.push( rf_push_pulse ),
|
||||
.pop( rf_pop ),
|
||||
.overrun( rf_overrun ),
|
||||
.count( rf_count ),
|
||||
.error_bit( rf_error_bit ),
|
||||
.fifo_reset( rx_reset ),
|
||||
.reset_status(lsr_mask)
|
||||
);
|
||||
|
||||
wire rcounter16_eq_7 = (rcounter16 == 4'd7);
|
||||
wire rcounter16_eq_0 = (rcounter16 == 4'd0);
|
||||
|
||||
wire [3:0] rcounter16_minus_1 = rcounter16 - 3'd1;
|
||||
|
||||
parameter sr_idle = 4'd0;
|
||||
parameter sr_rec_start = 4'd1;
|
||||
parameter sr_rec_bit = 4'd2;
|
||||
parameter sr_rec_parity = 4'd3;
|
||||
parameter sr_rec_stop = 4'd4;
|
||||
parameter sr_check_parity = 4'd5;
|
||||
parameter sr_rec_prepare = 4'd6;
|
||||
parameter sr_end_bit = 4'd7;
|
||||
parameter sr_ca_lc_parity = 4'd8;
|
||||
parameter sr_wait1 = 4'd9;
|
||||
parameter sr_push = 4'd10;
|
||||
|
||||
|
||||
always @(posedge clk or posedge wb_rst_i)
|
||||
begin
|
||||
if (wb_rst_i)
|
||||
begin
|
||||
rstate <= sr_idle;
|
||||
rcounter16 <= 0;
|
||||
rbit_counter <= 0;
|
||||
rparity_xor <= 1'b0;
|
||||
rframing_error <= 1'b0;
|
||||
rparity_error <= 1'b0;
|
||||
rparity <= 1'b0;
|
||||
rshift <= 0;
|
||||
rf_push <= 1'b0;
|
||||
rf_data_in <= 0;
|
||||
end
|
||||
else
|
||||
if (enable)
|
||||
begin
|
||||
case (rstate)
|
||||
sr_idle : begin
|
||||
rf_push <= 1'b0;
|
||||
rf_data_in <= 0;
|
||||
rcounter16 <= 4'b1110;
|
||||
if (srx_pad_i==1'b0 & ~break_error) // detected a pulse (start bit?)
|
||||
begin
|
||||
rstate <= sr_rec_start;
|
||||
end
|
||||
end
|
||||
sr_rec_start : begin
|
||||
rf_push <= 1'b0;
|
||||
if (rcounter16_eq_7) // check the pulse
|
||||
if (srx_pad_i==1'b1) // no start bit
|
||||
rstate <= sr_idle;
|
||||
else // start bit detected
|
||||
rstate <= sr_rec_prepare;
|
||||
rcounter16 <= rcounter16_minus_1;
|
||||
end
|
||||
sr_rec_prepare:begin
|
||||
case (lcr[/*`UART_LC_BITS*/1:0]) // number of bits in a word
|
||||
2'b00 : rbit_counter <= 3'b100;
|
||||
2'b01 : rbit_counter <= 3'b101;
|
||||
2'b10 : rbit_counter <= 3'b110;
|
||||
2'b11 : rbit_counter <= 3'b111;
|
||||
endcase
|
||||
if (rcounter16_eq_0)
|
||||
begin
|
||||
rstate <= sr_rec_bit;
|
||||
rcounter16 <= 4'b1110;
|
||||
rshift <= 0;
|
||||
end
|
||||
else
|
||||
rstate <= sr_rec_prepare;
|
||||
rcounter16 <= rcounter16_minus_1;
|
||||
end
|
||||
sr_rec_bit : begin
|
||||
if (rcounter16_eq_0)
|
||||
rstate <= sr_end_bit;
|
||||
if (rcounter16_eq_7) // read the bit
|
||||
case (lcr[/*`UART_LC_BITS*/1:0]) // number of bits in a word
|
||||
2'b00 : rshift[4:0] <= {srx_pad_i, rshift[4:1]};
|
||||
2'b01 : rshift[5:0] <= {srx_pad_i, rshift[5:1]};
|
||||
2'b10 : rshift[6:0] <= {srx_pad_i, rshift[6:1]};
|
||||
2'b11 : rshift[7:0] <= {srx_pad_i, rshift[7:1]};
|
||||
endcase
|
||||
rcounter16 <= rcounter16_minus_1;
|
||||
end
|
||||
sr_end_bit : begin
|
||||
if (rbit_counter==3'b0) // no more bits in word
|
||||
if (lcr[`UART_LC_PE]) // choose state based on parity
|
||||
rstate <= sr_rec_parity;
|
||||
else
|
||||
begin
|
||||
rstate <= sr_rec_stop;
|
||||
rparity_error <= 1'b0; // no parity - no error :)
|
||||
end
|
||||
else // else we have more bits to read
|
||||
begin
|
||||
rstate <= sr_rec_bit;
|
||||
rbit_counter <= rbit_counter - 3'd1;
|
||||
end
|
||||
rcounter16 <= 4'b1110;
|
||||
end
|
||||
sr_rec_parity: begin
|
||||
if (rcounter16_eq_7) // read the parity
|
||||
begin
|
||||
rparity <= srx_pad_i;
|
||||
rstate <= sr_ca_lc_parity;
|
||||
end
|
||||
rcounter16 <= rcounter16_minus_1;
|
||||
end
|
||||
sr_ca_lc_parity : begin // rcounter equals 6
|
||||
rcounter16 <= rcounter16_minus_1;
|
||||
rparity_xor <= ^{rshift,rparity}; // calculate parity on all incoming data
|
||||
rstate <= sr_check_parity;
|
||||
end
|
||||
sr_check_parity: begin // rcounter equals 5
|
||||
case ({lcr[`UART_LC_EP],lcr[`UART_LC_SP]})
|
||||
2'b00: rparity_error <= rparity_xor == 0; // no error if parity 1
|
||||
2'b01: rparity_error <= ~rparity; // parity should sticked to 1
|
||||
2'b10: rparity_error <= rparity_xor == 1; // error if parity is odd
|
||||
2'b11: rparity_error <= rparity; // parity should be sticked to 0
|
||||
endcase
|
||||
rcounter16 <= rcounter16_minus_1;
|
||||
rstate <= sr_wait1;
|
||||
end
|
||||
sr_wait1 : if (rcounter16_eq_0)
|
||||
begin
|
||||
rstate <= sr_rec_stop;
|
||||
rcounter16 <= 4'b1110;
|
||||
end
|
||||
else
|
||||
rcounter16 <= rcounter16_minus_1;
|
||||
sr_rec_stop : begin
|
||||
if (rcounter16_eq_7) // read the parity
|
||||
begin
|
||||
rframing_error <= !srx_pad_i; // no framing error if input is 1 (stop bit)
|
||||
rstate <= sr_push;
|
||||
end
|
||||
rcounter16 <= rcounter16_minus_1;
|
||||
end
|
||||
sr_push : begin
|
||||
///////////////////////////////////////
|
||||
// $display($time, ": received: %b", rf_data_in);
|
||||
if(srx_pad_i | break_error)
|
||||
begin
|
||||
if(break_error)
|
||||
rf_data_in <= {8'b0, 3'b100}; // break input (empty character) to receiver FIFO
|
||||
else
|
||||
rf_data_in <= {rshift, 1'b0, rparity_error, rframing_error};
|
||||
rf_push <= 1'b1;
|
||||
rstate <= sr_idle;
|
||||
end
|
||||
else if(~rframing_error) // There's always a framing before break_error -> wait for break or srx_pad_i
|
||||
begin
|
||||
rf_data_in <= {rshift, 1'b0, rparity_error, rframing_error};
|
||||
rf_push <= 1'b1;
|
||||
rcounter16 <= 4'b1110;
|
||||
rstate <= sr_rec_start;
|
||||
end
|
||||
|
||||
end
|
||||
default : rstate <= sr_idle;
|
||||
endcase
|
||||
end // if (enable)
|
||||
end // always of receiver
|
||||
|
||||
always @ (posedge clk or posedge wb_rst_i)
|
||||
begin
|
||||
if(wb_rst_i)
|
||||
rf_push_q <= 0;
|
||||
else
|
||||
rf_push_q <= rf_push;
|
||||
end
|
||||
|
||||
assign rf_push_pulse = rf_push & ~rf_push_q;
|
||||
|
||||
|
||||
//
|
||||
// Break condition detection.
|
||||
// Works in conjuction with the receiver state machine
|
||||
|
||||
reg [9:0] toc_value; // value to be set to timeout counter
|
||||
|
||||
always @(lcr)
|
||||
case (lcr[3:0])
|
||||
4'b0000 : toc_value = 447; // 7 bits
|
||||
4'b0100 : toc_value = 479; // 7.5 bits
|
||||
4'b0001, 4'b1000 : toc_value = 511; // 8 bits
|
||||
4'b1100 : toc_value = 543; // 8.5 bits
|
||||
4'b0010, 4'b0101, 4'b1001 : toc_value = 575; // 9 bits
|
||||
4'b0011, 4'b0110, 4'b1010, 4'b1101 : toc_value = 639; // 10 bits
|
||||
4'b0111, 4'b1011, 4'b1110 : toc_value = 703; // 11 bits
|
||||
4'b1111 : toc_value = 767; // 12 bits
|
||||
endcase // case(lcr[3:0])
|
||||
|
||||
wire [7:0] brc_value; // value to be set to break counter
|
||||
assign brc_value = toc_value[9:2]; // the same as timeout but 1 insead of 4 character times
|
||||
|
||||
always @(posedge clk or posedge wb_rst_i)
|
||||
begin
|
||||
if (wb_rst_i)
|
||||
counter_b <= 8'd159;
|
||||
else
|
||||
if (srx_pad_i)
|
||||
counter_b <= brc_value; // character time length - 1
|
||||
else
|
||||
if(enable & counter_b != 8'b0) // only work on enable times break not reached.
|
||||
counter_b <= counter_b - 8'd1; // decrement break counter
|
||||
end // always of break condition detection
|
||||
|
||||
///
|
||||
/// Timeout condition detection
|
||||
reg [9:0] counter_t; // counts the timeout condition clocks
|
||||
|
||||
always @(posedge clk or posedge wb_rst_i)
|
||||
begin
|
||||
if (wb_rst_i)
|
||||
counter_t <= 10'd639; // 10 bits for the default 8N1
|
||||
else
|
||||
if(rf_push_pulse || rf_pop || rf_count == 0) // counter is reset when RX FIFO is empty, accessed or above trigger level
|
||||
counter_t <= toc_value;
|
||||
else
|
||||
if (enable && counter_t != 10'b0) // we don't want to underflow
|
||||
counter_t <= counter_t - 10'd1;
|
||||
end
|
||||
|
||||
endmodule
|
||||
@ -0,0 +1,888 @@
|
||||
//////////////////////////////////////////////////////////////////////
|
||||
//// ////
|
||||
//// uart_regs.v ////
|
||||
//// ////
|
||||
//// ////
|
||||
//// This file is part of the "UART 16550 compatible" project ////
|
||||
//// http://www.opencores.org/cores/uart16550/ ////
|
||||
//// ////
|
||||
//// Documentation related to this project: ////
|
||||
//// - http://www.opencores.org/cores/uart16550/ ////
|
||||
//// ////
|
||||
//// Projects compatibility: ////
|
||||
//// - WISHBONE ////
|
||||
//// RS232 Protocol ////
|
||||
//// 16550D uart (mostly supported) ////
|
||||
//// ////
|
||||
//// Overview (main Features): ////
|
||||
//// Registers of the uart 16550 core ////
|
||||
//// ////
|
||||
//// Known problems (limits): ////
|
||||
//// Inserts 1 wait state in all WISHBONE transfers ////
|
||||
//// ////
|
||||
//// To Do: ////
|
||||
//// Nothing or verification. ////
|
||||
//// ////
|
||||
//// Author(s): ////
|
||||
//// - gorban@opencores.org ////
|
||||
//// - Jacob Gorban ////
|
||||
//// - Igor Mohor (igorm@opencores.org) ////
|
||||
//// ////
|
||||
//// Created: 2001/05/12 ////
|
||||
//// Last Updated: (See log for the revision history ////
|
||||
//// ////
|
||||
//// ////
|
||||
//////////////////////////////////////////////////////////////////////
|
||||
//// ////
|
||||
//// Copyright (C) 2000, 2001 Authors ////
|
||||
//// ////
|
||||
//// This source file may be used and distributed without ////
|
||||
//// restriction provided that this copyright statement is not ////
|
||||
//// removed from the file and that any derivative work contains ////
|
||||
//// the original copyright notice and the associated disclaimer. ////
|
||||
//// ////
|
||||
//// This source file is free software; you can redistribute it ////
|
||||
//// and/or modify it under the terms of the GNU Lesser General ////
|
||||
//// Public License as published by the Free Software Foundation; ////
|
||||
//// either version 2.1 of the License, or (at your option) any ////
|
||||
//// later version. ////
|
||||
//// ////
|
||||
//// This source is distributed in the hope that it will be ////
|
||||
//// useful, but WITHOUT ANY WARRANTY; without even the implied ////
|
||||
//// warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR ////
|
||||
//// PURPOSE. See the GNU Lesser General Public License for more ////
|
||||
//// details. ////
|
||||
//// ////
|
||||
//// You should have received a copy of the GNU Lesser General ////
|
||||
//// Public License along with this source; if not, download it ////
|
||||
//// from http://www.opencores.org/lgpl.shtml ////
|
||||
//// ////
|
||||
//////////////////////////////////////////////////////////////////////
|
||||
//
|
||||
// CVS Revision History
|
||||
//
|
||||
// $Log: not supported by cvs2svn $
|
||||
// Revision 1.41 2004/05/21 11:44:41 tadejm
|
||||
// Added synchronizer flops for RX input.
|
||||
//
|
||||
// Revision 1.40 2003/06/11 16:37:47 gorban
|
||||
// This fixes errors in some cases when data is being read and put to the FIFO at the same time. Patch is submitted by Scott Furman. Update is very recommended.
|
||||
//
|
||||
// Revision 1.39 2002/07/29 21:16:18 gorban
|
||||
// The uart_defines.v file is included again in sources.
|
||||
//
|
||||
// Revision 1.38 2002/07/22 23:02:23 gorban
|
||||
// Bug Fixes:
|
||||
// * Possible loss of sync and bad reception of stop bit on slow baud rates fixed.
|
||||
// Problem reported by Kenny.Tung.
|
||||
// * Bad (or lack of ) loopback handling fixed. Reported by Cherry Withers.
|
||||
//
|
||||
// Improvements:
|
||||
// * Made FIFO's as general inferrable memory where possible.
|
||||
// So on FPGA they should be inferred as RAM (Distributed RAM on Xilinx).
|
||||
// This saves about 1/3 of the Slice count and reduces P&R and synthesis times.
|
||||
//
|
||||
// * Added optional baudrate output (baud_o).
|
||||
// This is identical to BAUDOUT* signal on 16550 chip.
|
||||
// It outputs 16xbit_clock_rate - the divided clock.
|
||||
// It's disabled by default. Define UART_HAS_BAUDRATE_OUTPUT to use.
|
||||
//
|
||||
// Revision 1.37 2001/12/27 13:24:09 mohor
|
||||
// lsr[7] was not showing overrun errors.
|
||||
//
|
||||
// Revision 1.36 2001/12/20 13:25:46 mohor
|
||||
// rx push changed to be only one cycle wide.
|
||||
//
|
||||
// Revision 1.35 2001/12/19 08:03:34 mohor
|
||||
// Warnings cleared.
|
||||
//
|
||||
// Revision 1.34 2001/12/19 07:33:54 mohor
|
||||
// Synplicity was having troubles with the comment.
|
||||
//
|
||||
// Revision 1.33 2001/12/17 10:14:43 mohor
|
||||
// Things related to msr register changed. After THRE IRQ occurs, and one
|
||||
// character is written to the transmit fifo, the detection of the THRE bit in the
|
||||
// LSR is delayed for one character time.
|
||||
//
|
||||
// Revision 1.32 2001/12/14 13:19:24 mohor
|
||||
// MSR register fixed.
|
||||
//
|
||||
// Revision 1.31 2001/12/14 10:06:58 mohor
|
||||
// After reset modem status register MSR should be reset.
|
||||
//
|
||||
// Revision 1.30 2001/12/13 10:09:13 mohor
|
||||
// thre irq should be cleared only when being source of interrupt.
|
||||
//
|
||||
// Revision 1.29 2001/12/12 09:05:46 mohor
|
||||
// LSR status bit 0 was not cleared correctly in case of reseting the FCR (rx fifo).
|
||||
//
|
||||
// Revision 1.28 2001/12/10 19:52:41 gorban
|
||||
// Scratch register added
|
||||
//
|
||||
// Revision 1.27 2001/12/06 14:51:04 gorban
|
||||
// Bug in LSR[0] is fixed.
|
||||
// All WISHBONE signals are now sampled, so another wait-state is introduced on all transfers.
|
||||
//
|
||||
// Revision 1.26 2001/12/03 21:44:29 gorban
|
||||
// Updated specification documentation.
|
||||
// Added full 32-bit data bus interface, now as default.
|
||||
// Address is 5-bit wide in 32-bit data bus mode.
|
||||
// Added wb_sel_i input to the core. It's used in the 32-bit mode.
|
||||
// Added debug interface with two 32-bit read-only registers in 32-bit mode.
|
||||
// Bits 5 and 6 of LSR are now only cleared on TX FIFO write.
|
||||
// My small test bench is modified to work with 32-bit mode.
|
||||
//
|
||||
// Revision 1.25 2001/11/28 19:36:39 gorban
|
||||
// Fixed: timeout and break didn't pay attention to current data format when counting time
|
||||
//
|
||||
// Revision 1.24 2001/11/26 21:38:54 gorban
|
||||
// Lots of fixes:
|
||||
// Break condition wasn't handled correctly at all.
|
||||
// LSR bits could lose their values.
|
||||
// LSR value after reset was wrong.
|
||||
// Timing of THRE interrupt signal corrected.
|
||||
// LSR bit 0 timing corrected.
|
||||
//
|
||||
// Revision 1.23 2001/11/12 21:57:29 gorban
|
||||
// fixed more typo bugs
|
||||
//
|
||||
// Revision 1.22 2001/11/12 15:02:28 mohor
|
||||
// lsr1r error fixed.
|
||||
//
|
||||
// Revision 1.21 2001/11/12 14:57:27 mohor
|
||||
// ti_int_pnd error fixed.
|
||||
//
|
||||
// Revision 1.20 2001/11/12 14:50:27 mohor
|
||||
// ti_int_d error fixed.
|
||||
//
|
||||
// Revision 1.19 2001/11/10 12:43:21 gorban
|
||||
// Logic Synthesis bugs fixed. Some other minor changes
|
||||
//
|
||||
// Revision 1.18 2001/11/08 14:54:23 mohor
|
||||
// Comments in Slovene language deleted, few small fixes for better work of
|
||||
// old tools. IRQs need to be fix.
|
||||
//
|
||||
// Revision 1.17 2001/11/07 17:51:52 gorban
|
||||
// Heavily rewritten interrupt and LSR subsystems.
|
||||
// Many bugs hopefully squashed.
|
||||
//
|
||||
// Revision 1.16 2001/11/02 09:55:16 mohor
|
||||
// no message
|
||||
//
|
||||
// Revision 1.15 2001/10/31 15:19:22 gorban
|
||||
// Fixes to break and timeout conditions
|
||||
//
|
||||
// Revision 1.14 2001/10/29 17:00:46 gorban
|
||||
// fixed parity sending and tx_fifo resets over- and underrun
|
||||
//
|
||||
// Revision 1.13 2001/10/20 09:58:40 gorban
|
||||
// Small synopsis fixes
|
||||
//
|
||||
// Revision 1.12 2001/10/19 16:21:40 gorban
|
||||
// Changes data_out to be synchronous again as it should have been.
|
||||
//
|
||||
// Revision 1.11 2001/10/18 20:35:45 gorban
|
||||
// small fix
|
||||
//
|
||||
// Revision 1.10 2001/08/24 21:01:12 mohor
|
||||
// Things connected to parity changed.
|
||||
// Clock devider changed.
|
||||
//
|
||||
// Revision 1.9 2001/08/23 16:05:05 mohor
|
||||
// Stop bit bug fixed.
|
||||
// Parity bug fixed.
|
||||
// WISHBONE read cycle bug fixed,
|
||||
// OE indicator (Overrun Error) bug fixed.
|
||||
// PE indicator (Parity Error) bug fixed.
|
||||
// Register read bug fixed.
|
||||
//
|
||||
// Revision 1.10 2001/06/23 11:21:48 gorban
|
||||
// DL made 16-bit long. Fixed transmission/reception bugs.
|
||||
//
|
||||
// Revision 1.9 2001/05/31 20:08:01 gorban
|
||||
// FIFO changes and other corrections.
|
||||
//
|
||||
// Revision 1.8 2001/05/29 20:05:04 gorban
|
||||
// Fixed some bugs and synthesis problems.
|
||||
//
|
||||
// Revision 1.7 2001/05/27 17:37:49 gorban
|
||||
// Fixed many bugs. Updated spec. Changed FIFO files structure. See CHANGES.txt file.
|
||||
//
|
||||
// Revision 1.6 2001/05/21 19:12:02 gorban
|
||||
// Corrected some Linter messages.
|
||||
//
|
||||
// Revision 1.5 2001/05/17 18:34:18 gorban
|
||||
// First 'stable' release. Should be sythesizable now. Also added new header.
|
||||
//
|
||||
// Revision 1.0 2001-05-17 21:27:11+02 jacob
|
||||
// Initial revision
|
||||
//
|
||||
//
|
||||
|
||||
`include "uart_defines.v"
|
||||
|
||||
`define UART_DL1 7:0
|
||||
`define UART_DL2 15:8
|
||||
|
||||
module uart_regs
|
||||
#(parameter SIM = 0)
|
||||
(clk,
|
||||
wb_rst_i, wb_addr_i, wb_dat_i, wb_dat_o, wb_we_i, wb_re_i,
|
||||
|
||||
// additional signals
|
||||
modem_inputs,
|
||||
stx_pad_o, srx_pad_i,
|
||||
|
||||
rts_pad_o, dtr_pad_o, int_o
|
||||
`ifdef UART_HAS_BAUDRATE_OUTPUT
|
||||
, baud_o
|
||||
`endif
|
||||
|
||||
);
|
||||
|
||||
input clk;
|
||||
input wb_rst_i;
|
||||
input [2:0] wb_addr_i;
|
||||
input [7:0] wb_dat_i;
|
||||
output [7:0] wb_dat_o;
|
||||
input wb_we_i;
|
||||
input wb_re_i;
|
||||
|
||||
output stx_pad_o;
|
||||
input srx_pad_i;
|
||||
|
||||
input [3:0] modem_inputs;
|
||||
output rts_pad_o;
|
||||
output dtr_pad_o;
|
||||
output int_o;
|
||||
`ifdef UART_HAS_BAUDRATE_OUTPUT
|
||||
output baud_o;
|
||||
`endif
|
||||
|
||||
wire [3:0] modem_inputs;
|
||||
reg enable;
|
||||
`ifdef UART_HAS_BAUDRATE_OUTPUT
|
||||
assign baud_o = enable; // baud_o is actually the enable signal
|
||||
`endif
|
||||
|
||||
|
||||
wire stx_pad_o; // received from transmitter module
|
||||
wire srx_pad_i;
|
||||
wire srx_pad;
|
||||
|
||||
reg [7:0] wb_dat_o;
|
||||
|
||||
wire [2:0] wb_addr_i;
|
||||
wire [7:0] wb_dat_i;
|
||||
|
||||
|
||||
reg [3:0] ier;
|
||||
reg [3:0] iir;
|
||||
reg [1:0] fcr; /// bits 7 and 6 of fcr. Other bits are ignored
|
||||
reg [4:0] mcr;
|
||||
reg [7:0] lcr;
|
||||
reg [7:0] msr;
|
||||
reg [15:0] dl; // 32-bit divisor latch
|
||||
reg [7:0] scratch; // UART scratch register
|
||||
reg start_dlc; // activate dlc on writing to UART_DL1
|
||||
reg lsr_mask_d; // delay for lsr_mask condition
|
||||
reg msi_reset; // reset MSR 4 lower bits indicator
|
||||
//reg threi_clear; // THRE interrupt clear flag
|
||||
reg [15:0] dlc; // 32-bit divisor latch counter
|
||||
reg int_o;
|
||||
|
||||
reg [3:0] trigger_level; // trigger level of the receiver FIFO
|
||||
reg rx_reset;
|
||||
reg tx_reset;
|
||||
|
||||
wire dlab; // divisor latch access bit
|
||||
wire cts_pad_i, dsr_pad_i, ri_pad_i, dcd_pad_i; // modem status bits
|
||||
wire loopback; // loopback bit (MCR bit 4)
|
||||
wire cts, dsr, ri, dcd; // effective signals
|
||||
wire cts_c, dsr_c, ri_c, dcd_c; // Complement effective signals (considering loopback)
|
||||
wire rts_pad_o, dtr_pad_o; // modem control outputs
|
||||
|
||||
// LSR bits wires and regs
|
||||
wire [7:0] lsr;
|
||||
wire lsr0, lsr1, lsr2, lsr3, lsr4, lsr5, lsr6, lsr7;
|
||||
reg lsr0r, lsr1r, lsr2r, lsr3r, lsr4r, lsr5r, lsr6r, lsr7r;
|
||||
wire lsr_mask; // lsr_mask
|
||||
|
||||
//
|
||||
// ASSINGS
|
||||
//
|
||||
|
||||
assign lsr[7:0] = { lsr7r, lsr6r, lsr5r, lsr4r, lsr3r, lsr2r, lsr1r, lsr0r };
|
||||
|
||||
assign {cts_pad_i, dsr_pad_i, ri_pad_i, dcd_pad_i} = modem_inputs;
|
||||
assign {cts, dsr, ri, dcd} = ~{cts_pad_i,dsr_pad_i,ri_pad_i,dcd_pad_i};
|
||||
|
||||
assign {cts_c, dsr_c, ri_c, dcd_c} = loopback ? {mcr[`UART_MC_RTS],mcr[`UART_MC_DTR],mcr[`UART_MC_OUT1],mcr[`UART_MC_OUT2]}
|
||||
: {cts_pad_i,dsr_pad_i,ri_pad_i,dcd_pad_i};
|
||||
|
||||
assign dlab = lcr[`UART_LC_DL];
|
||||
assign loopback = mcr[4];
|
||||
|
||||
// assign modem outputs
|
||||
assign rts_pad_o = mcr[`UART_MC_RTS];
|
||||
assign dtr_pad_o = mcr[`UART_MC_DTR];
|
||||
|
||||
// Interrupt signals
|
||||
wire rls_int; // receiver line status interrupt
|
||||
wire rda_int; // receiver data available interrupt
|
||||
wire ti_int; // timeout indicator interrupt
|
||||
wire thre_int; // transmitter holding register empty interrupt
|
||||
wire ms_int; // modem status interrupt
|
||||
|
||||
// FIFO signals
|
||||
reg tf_push;
|
||||
reg rf_pop;
|
||||
wire [`UART_FIFO_REC_WIDTH-1:0] rf_data_out;
|
||||
wire rf_error_bit; // an error (parity or framing) is inside the fifo
|
||||
wire rf_overrun;
|
||||
wire rf_push_pulse;
|
||||
wire [`UART_FIFO_COUNTER_W-1:0] rf_count;
|
||||
wire [`UART_FIFO_COUNTER_W-1:0] tf_count;
|
||||
wire [2:0] tstate;
|
||||
wire [3:0] rstate;
|
||||
wire [9:0] counter_t;
|
||||
|
||||
wire thre_set_en; // THRE status is delayed one character time when a character is written to fifo.
|
||||
reg [7:0] block_cnt; // While counter counts, THRE status is blocked (delayed one character cycle)
|
||||
reg [7:0] block_value; // One character length minus stop bit
|
||||
|
||||
// Transmitter Instance
|
||||
wire serial_out;
|
||||
|
||||
uart_transmitter #(.SIM (SIM)) transmitter(clk, wb_rst_i, lcr, tf_push, wb_dat_i, enable, serial_out, tstate, tf_count, tx_reset, lsr_mask);
|
||||
|
||||
// Synchronizing and sampling serial RX input
|
||||
uart_sync_flops i_uart_sync_flops
|
||||
(
|
||||
.rst_i (wb_rst_i),
|
||||
.clk_i (clk),
|
||||
.stage1_rst_i (1'b0),
|
||||
.stage1_clk_en_i (1'b1),
|
||||
.async_dat_i (srx_pad_i),
|
||||
.sync_dat_o (srx_pad)
|
||||
);
|
||||
defparam i_uart_sync_flops.width = 1;
|
||||
defparam i_uart_sync_flops.init_value = 1'b1;
|
||||
|
||||
// handle loopback
|
||||
wire serial_in = loopback ? serial_out : srx_pad;
|
||||
assign stx_pad_o = loopback ? 1'b1 : serial_out;
|
||||
|
||||
// Receiver Instance
|
||||
uart_receiver receiver(clk, wb_rst_i, lcr, rf_pop, serial_in, enable,
|
||||
counter_t, rf_count, rf_data_out, rf_error_bit, rf_overrun, rx_reset, lsr_mask, rstate, rf_push_pulse);
|
||||
|
||||
|
||||
// Asynchronous reading here because the outputs are sampled in uart_wb.v file
|
||||
always @(dl or dlab or ier or iir or scratch
|
||||
or lcr or lsr or msr or rf_data_out or wb_addr_i or wb_re_i) // asynchrounous reading
|
||||
begin
|
||||
case (wb_addr_i)
|
||||
`UART_REG_RB : wb_dat_o = dlab ? dl[`UART_DL1] : rf_data_out[10:3];
|
||||
`UART_REG_IE : wb_dat_o = dlab ? dl[`UART_DL2] : {4'd0,ier};
|
||||
`UART_REG_II : wb_dat_o = {4'b1100,iir};
|
||||
`UART_REG_LC : wb_dat_o = lcr;
|
||||
`UART_REG_LS : wb_dat_o = lsr;
|
||||
`UART_REG_MS : wb_dat_o = msr;
|
||||
`UART_REG_SR : wb_dat_o = scratch;
|
||||
default: wb_dat_o = 8'b0; // ??
|
||||
endcase // case(wb_addr_i)
|
||||
end // always @ (dl or dlab or ier or iir or scratch...
|
||||
|
||||
|
||||
// rf_pop signal handling
|
||||
always @(posedge clk or posedge wb_rst_i)
|
||||
begin
|
||||
if (wb_rst_i)
|
||||
rf_pop <= 0;
|
||||
else
|
||||
if (rf_pop) // restore the signal to 0 after one clock cycle
|
||||
rf_pop <= 0;
|
||||
else
|
||||
if (wb_re_i && wb_addr_i == `UART_REG_RB && !dlab)
|
||||
rf_pop <= 1; // advance read pointer
|
||||
end
|
||||
|
||||
wire lsr_mask_condition;
|
||||
wire iir_read;
|
||||
wire msr_read;
|
||||
wire fifo_read;
|
||||
wire fifo_write;
|
||||
|
||||
assign lsr_mask_condition = (wb_re_i && wb_addr_i == `UART_REG_LS && !dlab);
|
||||
assign iir_read = (wb_re_i && wb_addr_i == `UART_REG_II && !dlab);
|
||||
assign msr_read = (wb_re_i && wb_addr_i == `UART_REG_MS && !dlab);
|
||||
assign fifo_read = (wb_re_i && wb_addr_i == `UART_REG_RB && !dlab);
|
||||
assign fifo_write = (wb_we_i && wb_addr_i == `UART_REG_TR && !dlab);
|
||||
|
||||
// lsr_mask_d delayed signal handling
|
||||
always @(posedge clk or posedge wb_rst_i)
|
||||
begin
|
||||
if (wb_rst_i)
|
||||
lsr_mask_d <= 0;
|
||||
else // reset bits in the Line Status Register
|
||||
lsr_mask_d <= lsr_mask_condition;
|
||||
end
|
||||
|
||||
// lsr_mask is rise detected
|
||||
assign lsr_mask = lsr_mask_condition && ~lsr_mask_d;
|
||||
|
||||
// msi_reset signal handling
|
||||
always @(posedge clk or posedge wb_rst_i)
|
||||
begin
|
||||
if (wb_rst_i)
|
||||
msi_reset <= 1;
|
||||
else
|
||||
if (msi_reset)
|
||||
msi_reset <= 0;
|
||||
else
|
||||
if (msr_read)
|
||||
msi_reset <= 1; // reset bits in Modem Status Register
|
||||
end
|
||||
|
||||
|
||||
//
|
||||
// WRITES AND RESETS //
|
||||
//
|
||||
// Line Control Register
|
||||
always @(posedge clk or posedge wb_rst_i)
|
||||
if (wb_rst_i)
|
||||
lcr <= 8'b00000011; // 8n1 setting
|
||||
else
|
||||
if (wb_we_i && wb_addr_i==`UART_REG_LC)
|
||||
lcr <= wb_dat_i;
|
||||
|
||||
// Interrupt Enable Register or UART_DL2
|
||||
always @(posedge clk or posedge wb_rst_i)
|
||||
if (wb_rst_i)
|
||||
begin
|
||||
ier <= 4'b0000; // no interrupts after reset
|
||||
`ifdef PRESCALER_PRESET_HARD
|
||||
dl[`UART_DL2] <= `PRESCALER_HIGH_PRESET;
|
||||
`else
|
||||
dl[`UART_DL2] <= 8'b0;
|
||||
`endif
|
||||
end
|
||||
else
|
||||
if (wb_we_i && wb_addr_i==`UART_REG_IE)
|
||||
if (dlab)
|
||||
begin
|
||||
dl[`UART_DL2] <=
|
||||
`ifdef PRESCALER_PRESET_HARD
|
||||
dl[`UART_DL2];
|
||||
`else
|
||||
wb_dat_i;
|
||||
`endif
|
||||
end
|
||||
else
|
||||
ier <= wb_dat_i[3:0]; // ier uses only 4 lsb
|
||||
|
||||
|
||||
// FIFO Control Register and rx_reset, tx_reset signals
|
||||
always @(posedge clk or posedge wb_rst_i)
|
||||
if (wb_rst_i) begin
|
||||
fcr <= 2'b11;
|
||||
rx_reset <= 0;
|
||||
tx_reset <= 0;
|
||||
end else
|
||||
if (wb_we_i && wb_addr_i==`UART_REG_FC) begin
|
||||
fcr <= wb_dat_i[7:6];
|
||||
rx_reset <= wb_dat_i[1];
|
||||
tx_reset <= wb_dat_i[2];
|
||||
end else begin
|
||||
rx_reset <= 0;
|
||||
tx_reset <= 0;
|
||||
end
|
||||
|
||||
// Modem Control Register
|
||||
always @(posedge clk or posedge wb_rst_i)
|
||||
if (wb_rst_i)
|
||||
mcr <= 5'b0;
|
||||
else
|
||||
if (wb_we_i && wb_addr_i==`UART_REG_MC)
|
||||
mcr <= wb_dat_i[4:0];
|
||||
|
||||
// Scratch register
|
||||
// Line Control Register
|
||||
always @(posedge clk or posedge wb_rst_i)
|
||||
if (wb_rst_i)
|
||||
scratch <= 0; // 8n1 setting
|
||||
else
|
||||
if (wb_we_i && wb_addr_i==`UART_REG_SR)
|
||||
scratch <= wb_dat_i;
|
||||
|
||||
// TX_FIFO or UART_DL1
|
||||
always @(posedge clk or posedge wb_rst_i)
|
||||
if (wb_rst_i)
|
||||
begin
|
||||
`ifdef PRESCALER_PRESET_HARD
|
||||
dl[`UART_DL1] <= `PRESCALER_LOW_PRESET;
|
||||
`else
|
||||
dl[`UART_DL1] <= 8'b0;
|
||||
`endif
|
||||
tf_push <= 1'b0;
|
||||
start_dlc <= 1'b0;
|
||||
end
|
||||
else
|
||||
if (wb_we_i && wb_addr_i==`UART_REG_TR)
|
||||
if (dlab)
|
||||
begin
|
||||
`ifdef PRESCALER_PRESET_HARD
|
||||
dl[`UART_DL1] <= dl[`UART_DL1];
|
||||
`else
|
||||
dl[`UART_DL1] <= wb_dat_i;
|
||||
`endif
|
||||
start_dlc <= 1'b1; // enable DL counter
|
||||
tf_push <= 1'b0;
|
||||
end
|
||||
else
|
||||
begin
|
||||
tf_push <= 1'b1;
|
||||
start_dlc <= 1'b0;
|
||||
end // else: !if(dlab)
|
||||
else
|
||||
begin
|
||||
start_dlc <= 1'b0;
|
||||
tf_push <= 1'b0;
|
||||
end // else: !if(dlab)
|
||||
|
||||
// Receiver FIFO trigger level selection logic (asynchronous mux)
|
||||
always @(fcr)
|
||||
case (fcr[`UART_FC_TL])
|
||||
2'b00 : trigger_level = 1;
|
||||
2'b01 : trigger_level = 4;
|
||||
2'b10 : trigger_level = 8;
|
||||
2'b11 : trigger_level = 14;
|
||||
endcase // case(fcr[`UART_FC_TL])
|
||||
|
||||
//
|
||||
// STATUS REGISTERS //
|
||||
//
|
||||
|
||||
// Modem Status Register
|
||||
reg [3:0] delayed_modem_signals;
|
||||
always @(posedge clk or posedge wb_rst_i)
|
||||
begin
|
||||
if (wb_rst_i)
|
||||
begin
|
||||
msr <= 0;
|
||||
delayed_modem_signals[3:0] <= 0;
|
||||
end
|
||||
else begin
|
||||
msr[`UART_MS_DDCD:`UART_MS_DCTS] <= msi_reset ? 4'b0 :
|
||||
msr[`UART_MS_DDCD:`UART_MS_DCTS] | ({dcd, ri, dsr, cts} ^ delayed_modem_signals[3:0]);
|
||||
msr[`UART_MS_CDCD:`UART_MS_CCTS] <= {dcd_c, ri_c, dsr_c, cts_c};
|
||||
delayed_modem_signals[3:0] <= {dcd, ri, dsr, cts};
|
||||
end
|
||||
end
|
||||
|
||||
|
||||
// Line Status Register
|
||||
|
||||
// activation conditions
|
||||
assign lsr0 = (rf_count==0 && rf_push_pulse); // data in receiver fifo available set condition
|
||||
assign lsr1 = rf_overrun; // Receiver overrun error
|
||||
assign lsr2 = rf_data_out[1]; // parity error bit
|
||||
assign lsr3 = rf_data_out[0]; // framing error bit
|
||||
assign lsr4 = rf_data_out[2]; // break error in the character
|
||||
assign lsr5 = (tf_count==5'b0 && thre_set_en); // transmitter fifo is empty
|
||||
assign lsr6 = (tf_count==5'b0 && thre_set_en && (tstate == /*`S_IDLE */ 0)); // transmitter empty
|
||||
assign lsr7 = rf_error_bit | rf_overrun;
|
||||
|
||||
// lsr bit0 (receiver data available)
|
||||
reg lsr0_d;
|
||||
|
||||
always @(posedge clk or posedge wb_rst_i)
|
||||
if (wb_rst_i) lsr0_d <= 0;
|
||||
else lsr0_d <= lsr0;
|
||||
|
||||
always @(posedge clk or posedge wb_rst_i)
|
||||
if (wb_rst_i) lsr0r <= 0;
|
||||
else lsr0r <= (rf_count==1 && rf_pop && !rf_push_pulse || rx_reset) ? 1'b0 : // deassert condition
|
||||
lsr0r || (lsr0 && ~lsr0_d); // set on rise of lsr0 and keep asserted until deasserted
|
||||
|
||||
// lsr bit 1 (receiver overrun)
|
||||
reg lsr1_d; // delayed
|
||||
|
||||
always @(posedge clk or posedge wb_rst_i)
|
||||
if (wb_rst_i) lsr1_d <= 0;
|
||||
else lsr1_d <= lsr1;
|
||||
|
||||
always @(posedge clk or posedge wb_rst_i)
|
||||
if (wb_rst_i) lsr1r <= 0;
|
||||
else lsr1r <= lsr_mask ? 1'b0 : lsr1r || (lsr1 && ~lsr1_d); // set on rise
|
||||
|
||||
// lsr bit 2 (parity error)
|
||||
reg lsr2_d; // delayed
|
||||
|
||||
always @(posedge clk or posedge wb_rst_i)
|
||||
if (wb_rst_i) lsr2_d <= 0;
|
||||
else lsr2_d <= lsr2;
|
||||
|
||||
always @(posedge clk or posedge wb_rst_i)
|
||||
if (wb_rst_i) lsr2r <= 0;
|
||||
else lsr2r <= lsr_mask ? 1'b0 : lsr2r || (lsr2 && ~lsr2_d); // set on rise
|
||||
|
||||
// lsr bit 3 (framing error)
|
||||
reg lsr3_d; // delayed
|
||||
|
||||
always @(posedge clk or posedge wb_rst_i)
|
||||
if (wb_rst_i) lsr3_d <= 0;
|
||||
else lsr3_d <= lsr3;
|
||||
|
||||
always @(posedge clk or posedge wb_rst_i)
|
||||
if (wb_rst_i) lsr3r <= 0;
|
||||
else lsr3r <= lsr_mask ? 1'b0 : lsr3r || (lsr3 && ~lsr3_d); // set on rise
|
||||
|
||||
// lsr bit 4 (break indicator)
|
||||
reg lsr4_d; // delayed
|
||||
|
||||
always @(posedge clk or posedge wb_rst_i)
|
||||
if (wb_rst_i) lsr4_d <= 0;
|
||||
else lsr4_d <= lsr4;
|
||||
|
||||
always @(posedge clk or posedge wb_rst_i)
|
||||
if (wb_rst_i) lsr4r <= 0;
|
||||
else lsr4r <= lsr_mask ? 1'b0 : lsr4r || (lsr4 && ~lsr4_d);
|
||||
|
||||
// lsr bit 5 (transmitter fifo is empty)
|
||||
reg lsr5_d;
|
||||
|
||||
always @(posedge clk or posedge wb_rst_i)
|
||||
if (wb_rst_i) lsr5_d <= 1;
|
||||
else lsr5_d <= lsr5;
|
||||
|
||||
always @(posedge clk or posedge wb_rst_i)
|
||||
if (wb_rst_i) lsr5r <= 1;
|
||||
else lsr5r <= (fifo_write) ? 1'b0 : lsr5r || (lsr5 && ~lsr5_d);
|
||||
|
||||
// lsr bit 6 (transmitter empty indicator)
|
||||
reg lsr6_d;
|
||||
|
||||
always @(posedge clk or posedge wb_rst_i)
|
||||
if (wb_rst_i) lsr6_d <= 1;
|
||||
else lsr6_d <= lsr6;
|
||||
|
||||
always @(posedge clk or posedge wb_rst_i)
|
||||
if (wb_rst_i) lsr6r <= 1;
|
||||
else lsr6r <= (fifo_write) ? 1'b0 : lsr6r || (lsr6 && ~lsr6_d);
|
||||
|
||||
// lsr bit 7 (error in fifo)
|
||||
reg lsr7_d;
|
||||
|
||||
always @(posedge clk or posedge wb_rst_i)
|
||||
if (wb_rst_i) lsr7_d <= 0;
|
||||
else lsr7_d <= lsr7;
|
||||
|
||||
always @(posedge clk or posedge wb_rst_i)
|
||||
if (wb_rst_i) lsr7r <= 0;
|
||||
else lsr7r <= lsr_mask ? 1'b0 : lsr7r || (lsr7 && ~lsr7_d);
|
||||
|
||||
// Frequency divider
|
||||
always @(posedge clk or posedge wb_rst_i)
|
||||
begin
|
||||
if (wb_rst_i)
|
||||
dlc <= 0;
|
||||
else
|
||||
if (start_dlc | ~ (|dlc))
|
||||
dlc <= dl - 16'd1; // preset counter
|
||||
else
|
||||
dlc <= dlc - 16'd1; // decrement counter
|
||||
end
|
||||
|
||||
// Enable signal generation logic
|
||||
always @(posedge clk or posedge wb_rst_i)
|
||||
begin
|
||||
if (wb_rst_i)
|
||||
enable <= 1'b0;
|
||||
else
|
||||
if (|dl & ~(|dlc)) // dl>0 & dlc==0
|
||||
enable <= 1'b1;
|
||||
else
|
||||
enable <= 1'b0;
|
||||
end
|
||||
|
||||
// Delaying THRE status for one character cycle after a character is written to an empty fifo.
|
||||
always @(lcr)
|
||||
case (lcr[3:0])
|
||||
4'b0000 : block_value = 95; // 6 bits
|
||||
4'b0100 : block_value = 103; // 6.5 bits
|
||||
4'b0001, 4'b1000 : block_value = 111; // 7 bits
|
||||
4'b1100 : block_value = 119; // 7.5 bits
|
||||
4'b0010, 4'b0101, 4'b1001 : block_value = 127; // 8 bits
|
||||
4'b0011, 4'b0110, 4'b1010, 4'b1101 : block_value = 143; // 9 bits
|
||||
4'b0111, 4'b1011, 4'b1110 : block_value = 159; // 10 bits
|
||||
4'b1111 : block_value = 175; // 11 bits
|
||||
endcase // case(lcr[3:0])
|
||||
|
||||
// Counting time of one character minus stop bit
|
||||
always @(posedge clk or posedge wb_rst_i)
|
||||
begin
|
||||
if (wb_rst_i)
|
||||
block_cnt <= 8'd0;
|
||||
else
|
||||
if(lsr5r & fifo_write) // THRE bit set & write to fifo occured
|
||||
block_cnt <= SIM ? 8'd1 : block_value;
|
||||
else
|
||||
if (enable & block_cnt != 8'b0) // only work on enable times
|
||||
block_cnt <= block_cnt - 8'd1; // decrement break counter
|
||||
end // always of break condition detection
|
||||
|
||||
// Generating THRE status enable signal
|
||||
assign thre_set_en = ~(|block_cnt);
|
||||
|
||||
|
||||
//
|
||||
// INTERRUPT LOGIC
|
||||
//
|
||||
|
||||
assign rls_int = ier[`UART_IE_RLS] && (lsr[`UART_LS_OE] || lsr[`UART_LS_PE] || lsr[`UART_LS_FE] || lsr[`UART_LS_BI]);
|
||||
assign rda_int = ier[`UART_IE_RDA] && (rf_count >= {1'b0,trigger_level});
|
||||
assign thre_int = ier[`UART_IE_THRE] && lsr[`UART_LS_TFE];
|
||||
assign ms_int = ier[`UART_IE_MS] && (| msr[3:0]);
|
||||
assign ti_int = ier[`UART_IE_RDA] && (counter_t == 10'b0) && (|rf_count);
|
||||
|
||||
reg rls_int_d;
|
||||
reg thre_int_d;
|
||||
reg ms_int_d;
|
||||
reg ti_int_d;
|
||||
reg rda_int_d;
|
||||
|
||||
// delay lines
|
||||
always @(posedge clk or posedge wb_rst_i)
|
||||
if (wb_rst_i) rls_int_d <= 0;
|
||||
else rls_int_d <= rls_int;
|
||||
|
||||
always @(posedge clk or posedge wb_rst_i)
|
||||
if (wb_rst_i) rda_int_d <= 0;
|
||||
else rda_int_d <= rda_int;
|
||||
|
||||
always @(posedge clk or posedge wb_rst_i)
|
||||
if (wb_rst_i) thre_int_d <= 0;
|
||||
else thre_int_d <= thre_int;
|
||||
|
||||
always @(posedge clk or posedge wb_rst_i)
|
||||
if (wb_rst_i) ms_int_d <= 0;
|
||||
else ms_int_d <= ms_int;
|
||||
|
||||
always @(posedge clk or posedge wb_rst_i)
|
||||
if (wb_rst_i) ti_int_d <= 0;
|
||||
else ti_int_d <= ti_int;
|
||||
|
||||
// rise detection signals
|
||||
|
||||
wire rls_int_rise;
|
||||
wire thre_int_rise;
|
||||
wire ms_int_rise;
|
||||
wire ti_int_rise;
|
||||
wire rda_int_rise;
|
||||
|
||||
assign rda_int_rise = rda_int & ~rda_int_d;
|
||||
assign rls_int_rise = rls_int & ~rls_int_d;
|
||||
assign thre_int_rise = thre_int & ~thre_int_d;
|
||||
assign ms_int_rise = ms_int & ~ms_int_d;
|
||||
assign ti_int_rise = ti_int & ~ti_int_d;
|
||||
|
||||
// interrupt pending flags
|
||||
reg rls_int_pnd;
|
||||
reg rda_int_pnd;
|
||||
reg thre_int_pnd;
|
||||
reg ms_int_pnd;
|
||||
reg ti_int_pnd;
|
||||
|
||||
// interrupt pending flags assignments
|
||||
always @(posedge clk or posedge wb_rst_i)
|
||||
if (wb_rst_i) rls_int_pnd <= 0;
|
||||
else
|
||||
rls_int_pnd <= lsr_mask ? 1'b0 : // reset condition
|
||||
rls_int_rise ? 1'b1 : // latch condition
|
||||
rls_int_pnd && ier[`UART_IE_RLS]; // default operation: remove if masked
|
||||
|
||||
always @(posedge clk or posedge wb_rst_i)
|
||||
if (wb_rst_i) rda_int_pnd <= 0;
|
||||
else
|
||||
rda_int_pnd <= ((rf_count == {1'b0,trigger_level}) && fifo_read) ? 1'b0 : // reset condition
|
||||
rda_int_rise ? 1'b1 : // latch condition
|
||||
rda_int_pnd && ier[`UART_IE_RDA]; // default operation: remove if masked
|
||||
|
||||
always @(posedge clk or posedge wb_rst_i)
|
||||
if (wb_rst_i) thre_int_pnd <= 0;
|
||||
else
|
||||
thre_int_pnd <= fifo_write || (iir_read & ~iir[`UART_II_IP] & iir[`UART_II_II] == `UART_II_THRE)? 1'b0 :
|
||||
thre_int_rise ? 1'b1 :
|
||||
thre_int_pnd && ier[`UART_IE_THRE];
|
||||
|
||||
always @(posedge clk or posedge wb_rst_i)
|
||||
if (wb_rst_i) ms_int_pnd <= 0;
|
||||
else
|
||||
ms_int_pnd <= msr_read ? 1'b0 :
|
||||
ms_int_rise ? 1'b1 :
|
||||
ms_int_pnd && ier[`UART_IE_MS];
|
||||
|
||||
always @(posedge clk or posedge wb_rst_i)
|
||||
if (wb_rst_i) ti_int_pnd <= 0;
|
||||
else
|
||||
ti_int_pnd <= fifo_read ? 1'b0 :
|
||||
ti_int_rise ? 1'b1 :
|
||||
ti_int_pnd && ier[`UART_IE_RDA];
|
||||
// end of pending flags
|
||||
|
||||
// INT_O logic
|
||||
always @(posedge clk or posedge wb_rst_i)
|
||||
begin
|
||||
if (wb_rst_i)
|
||||
int_o <= 1'b0;
|
||||
else
|
||||
int_o <=
|
||||
rls_int_pnd ? ~lsr_mask :
|
||||
rda_int_pnd ? 1'b1 :
|
||||
ti_int_pnd ? ~fifo_read :
|
||||
thre_int_pnd ? !(fifo_write & iir_read) :
|
||||
ms_int_pnd ? ~msr_read :
|
||||
1'd0; // if no interrupt are pending
|
||||
end
|
||||
|
||||
|
||||
// Interrupt Identification register
|
||||
always @(posedge clk or posedge wb_rst_i)
|
||||
begin
|
||||
if (wb_rst_i)
|
||||
iir <= 1;
|
||||
else
|
||||
if (rls_int_pnd) // interrupt is pending
|
||||
begin
|
||||
iir[`UART_II_II] <= `UART_II_RLS; // set identification register to correct value
|
||||
iir[`UART_II_IP] <= 1'b0; // and clear the IIR bit 0 (interrupt pending)
|
||||
end else // the sequence of conditions determines priority of interrupt identification
|
||||
if (rda_int)
|
||||
begin
|
||||
iir[`UART_II_II] <= `UART_II_RDA;
|
||||
iir[`UART_II_IP] <= 1'b0;
|
||||
end
|
||||
else if (ti_int_pnd)
|
||||
begin
|
||||
iir[`UART_II_II] <= `UART_II_TI;
|
||||
iir[`UART_II_IP] <= 1'b0;
|
||||
end
|
||||
else if (thre_int_pnd)
|
||||
begin
|
||||
iir[`UART_II_II] <= `UART_II_THRE;
|
||||
iir[`UART_II_IP] <= 1'b0;
|
||||
end
|
||||
else if (ms_int_pnd)
|
||||
begin
|
||||
iir[`UART_II_II] <= `UART_II_MS;
|
||||
iir[`UART_II_IP] <= 1'b0;
|
||||
end else // no interrupt is pending
|
||||
begin
|
||||
iir[`UART_II_II] <= 0;
|
||||
iir[`UART_II_IP] <= 1'b1;
|
||||
end
|
||||
end
|
||||
|
||||
endmodule
|
||||
@ -0,0 +1,316 @@
|
||||
//////////////////////////////////////////////////////////////////////
|
||||
//// ////
|
||||
//// uart_rfifo.v (Modified from uart_fifo.v) ////
|
||||
//// ////
|
||||
//// ////
|
||||
//// This file is part of the "UART 16550 compatible" project ////
|
||||
//// http://www.opencores.org/cores/uart16550/ ////
|
||||
//// ////
|
||||
//// Documentation related to this project: ////
|
||||
//// - http://www.opencores.org/cores/uart16550/ ////
|
||||
//// ////
|
||||
//// Projects compatibility: ////
|
||||
//// - WISHBONE ////
|
||||
//// RS232 Protocol ////
|
||||
//// 16550D uart (mostly supported) ////
|
||||
//// ////
|
||||
//// Overview (main Features): ////
|
||||
//// UART core receiver FIFO ////
|
||||
//// ////
|
||||
//// To Do: ////
|
||||
//// Nothing. ////
|
||||
//// ////
|
||||
//// Author(s): ////
|
||||
//// - gorban@opencores.org ////
|
||||
//// - Jacob Gorban ////
|
||||
//// - Igor Mohor (igorm@opencores.org) ////
|
||||
//// ////
|
||||
//// Created: 2001/05/12 ////
|
||||
//// Last Updated: 2002/07/22 ////
|
||||
//// (See log for the revision history) ////
|
||||
//// ////
|
||||
//// ////
|
||||
//////////////////////////////////////////////////////////////////////
|
||||
//// ////
|
||||
//// Copyright (C) 2000, 2001 Authors ////
|
||||
//// ////
|
||||
//// This source file may be used and distributed without ////
|
||||
//// restriction provided that this copyright statement is not ////
|
||||
//// removed from the file and that any derivative work contains ////
|
||||
//// the original copyright notice and the associated disclaimer. ////
|
||||
//// ////
|
||||
//// This source file is free software; you can redistribute it ////
|
||||
//// and/or modify it under the terms of the GNU Lesser General ////
|
||||
//// Public License as published by the Free Software Foundation; ////
|
||||
//// either version 2.1 of the License, or (at your option) any ////
|
||||
//// later version. ////
|
||||
//// ////
|
||||
//// This source is distributed in the hope that it will be ////
|
||||
//// useful, but WITHOUT ANY WARRANTY; without even the implied ////
|
||||
//// warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR ////
|
||||
//// PURPOSE. See the GNU Lesser General Public License for more ////
|
||||
//// details. ////
|
||||
//// ////
|
||||
//// You should have received a copy of the GNU Lesser General ////
|
||||
//// Public License along with this source; if not, download it ////
|
||||
//// from http://www.opencores.org/lgpl.shtml ////
|
||||
//// ////
|
||||
//////////////////////////////////////////////////////////////////////
|
||||
//
|
||||
// CVS Revision History
|
||||
//
|
||||
// $Log: not supported by cvs2svn $
|
||||
// Revision 1.3 2003/06/11 16:37:47 gorban
|
||||
// This fixes errors in some cases when data is being read and put to the FIFO at the same time. Patch is submitted by Scott Furman. Update is very recommended.
|
||||
//
|
||||
// Revision 1.2 2002/07/29 21:16:18 gorban
|
||||
// The uart_defines.v file is included again in sources.
|
||||
//
|
||||
// Revision 1.1 2002/07/22 23:02:23 gorban
|
||||
// Bug Fixes:
|
||||
// * Possible loss of sync and bad reception of stop bit on slow baud rates fixed.
|
||||
// Problem reported by Kenny.Tung.
|
||||
// * Bad (or lack of ) loopback handling fixed. Reported by Cherry Withers.
|
||||
//
|
||||
// Improvements:
|
||||
// * Made FIFO's as general inferrable memory where possible.
|
||||
// So on FPGA they should be inferred as RAM (Distributed RAM on Xilinx).
|
||||
// This saves about 1/3 of the Slice count and reduces P&R and synthesis times.
|
||||
//
|
||||
// * Added optional baudrate output (baud_o).
|
||||
// This is identical to BAUDOUT* signal on 16550 chip.
|
||||
// It outputs 16xbit_clock_rate - the divided clock.
|
||||
// It's disabled by default. Define UART_HAS_BAUDRATE_OUTPUT to use.
|
||||
//
|
||||
// Revision 1.16 2001/12/20 13:25:46 mohor
|
||||
// rx push changed to be only one cycle wide.
|
||||
//
|
||||
// Revision 1.15 2001/12/18 09:01:07 mohor
|
||||
// Bug that was entered in the last update fixed (rx state machine).
|
||||
//
|
||||
// Revision 1.14 2001/12/17 14:46:48 mohor
|
||||
// overrun signal was moved to separate block because many sequential lsr
|
||||
// reads were preventing data from being written to rx fifo.
|
||||
// underrun signal was not used and was removed from the project.
|
||||
//
|
||||
// Revision 1.13 2001/11/26 21:38:54 gorban
|
||||
// Lots of fixes:
|
||||
// Break condition wasn't handled correctly at all.
|
||||
// LSR bits could lose their values.
|
||||
// LSR value after reset was wrong.
|
||||
// Timing of THRE interrupt signal corrected.
|
||||
// LSR bit 0 timing corrected.
|
||||
//
|
||||
// Revision 1.12 2001/11/08 14:54:23 mohor
|
||||
// Comments in Slovene language deleted, few small fixes for better work of
|
||||
// old tools. IRQs need to be fix.
|
||||
//
|
||||
// Revision 1.11 2001/11/07 17:51:52 gorban
|
||||
// Heavily rewritten interrupt and LSR subsystems.
|
||||
// Many bugs hopefully squashed.
|
||||
//
|
||||
// Revision 1.10 2001/10/20 09:58:40 gorban
|
||||
// Small synopsis fixes
|
||||
//
|
||||
// Revision 1.9 2001/08/24 21:01:12 mohor
|
||||
// Things connected to parity changed.
|
||||
// Clock devider changed.
|
||||
//
|
||||
// Revision 1.8 2001/08/24 08:48:10 mohor
|
||||
// FIFO was not cleared after the data was read bug fixed.
|
||||
//
|
||||
// Revision 1.7 2001/08/23 16:05:05 mohor
|
||||
// Stop bit bug fixed.
|
||||
// Parity bug fixed.
|
||||
// WISHBONE read cycle bug fixed,
|
||||
// OE indicator (Overrun Error) bug fixed.
|
||||
// PE indicator (Parity Error) bug fixed.
|
||||
// Register read bug fixed.
|
||||
//
|
||||
// Revision 1.3 2001/05/31 20:08:01 gorban
|
||||
// FIFO changes and other corrections.
|
||||
//
|
||||
// Revision 1.3 2001/05/27 17:37:48 gorban
|
||||
// Fixed many bugs. Updated spec. Changed FIFO files structure. See CHANGES.txt file.
|
||||
//
|
||||
// Revision 1.2 2001/05/17 18:34:18 gorban
|
||||
// First 'stable' release. Should be sythesizable now. Also added new header.
|
||||
//
|
||||
// Revision 1.0 2001-05-17 21:27:12+02 jacob
|
||||
// Initial revision
|
||||
//
|
||||
//
|
||||
|
||||
`include "uart_defines.v"
|
||||
|
||||
module uart_rfifo (clk,
|
||||
wb_rst_i, data_in, data_out,
|
||||
// Control signals
|
||||
push, // push strobe, active high
|
||||
pop, // pop strobe, active high
|
||||
// status signals
|
||||
overrun,
|
||||
count,
|
||||
error_bit,
|
||||
fifo_reset,
|
||||
reset_status
|
||||
);
|
||||
|
||||
|
||||
// FIFO parameters
|
||||
parameter fifo_width = `UART_FIFO_WIDTH;
|
||||
parameter fifo_depth = `UART_FIFO_DEPTH;
|
||||
parameter fifo_pointer_w = `UART_FIFO_POINTER_W;
|
||||
parameter fifo_counter_w = `UART_FIFO_COUNTER_W;
|
||||
|
||||
input clk;
|
||||
input wb_rst_i;
|
||||
input push;
|
||||
input pop;
|
||||
input [fifo_width-1:0] data_in;
|
||||
input fifo_reset;
|
||||
input reset_status;
|
||||
|
||||
output [fifo_width-1:0] data_out;
|
||||
output overrun;
|
||||
output [fifo_counter_w-1:0] count;
|
||||
output error_bit;
|
||||
|
||||
wire [fifo_width-1:0] data_out;
|
||||
wire [7:0] data8_out;
|
||||
// flags FIFO
|
||||
reg [2:0] fifo[fifo_depth-1:0];
|
||||
|
||||
// FIFO pointers
|
||||
reg [fifo_pointer_w-1:0] top;
|
||||
reg [fifo_pointer_w-1:0] bottom;
|
||||
|
||||
reg [fifo_counter_w-1:0] count;
|
||||
reg overrun;
|
||||
|
||||
wire [fifo_pointer_w-1:0] top_plus_1 = top + 4'h1;
|
||||
|
||||
raminfr #(fifo_pointer_w,8,fifo_depth) rfifo
|
||||
(.clk(clk),
|
||||
.we(push),
|
||||
.a(top),
|
||||
.dpra(bottom),
|
||||
.di(data_in[fifo_width-1:fifo_width-8]),
|
||||
.dpo(data8_out)
|
||||
);
|
||||
|
||||
always @(posedge clk or posedge wb_rst_i) // synchronous FIFO
|
||||
begin
|
||||
if (wb_rst_i)
|
||||
begin
|
||||
top <= 0;
|
||||
bottom <= 0;
|
||||
count <= 0;
|
||||
fifo[0] <= 0;
|
||||
fifo[1] <= 0;
|
||||
fifo[2] <= 0;
|
||||
fifo[3] <= 0;
|
||||
fifo[4] <= 0;
|
||||
fifo[5] <= 0;
|
||||
fifo[6] <= 0;
|
||||
fifo[7] <= 0;
|
||||
fifo[8] <= 0;
|
||||
fifo[9] <= 0;
|
||||
fifo[10] <= 0;
|
||||
fifo[11] <= 0;
|
||||
fifo[12] <= 0;
|
||||
fifo[13] <= 0;
|
||||
fifo[14] <= 0;
|
||||
fifo[15] <= 0;
|
||||
end
|
||||
else
|
||||
if (fifo_reset) begin
|
||||
top <= 0;
|
||||
bottom <= 0;
|
||||
count <= 0;
|
||||
fifo[0] <= 0;
|
||||
fifo[1] <= 0;
|
||||
fifo[2] <= 0;
|
||||
fifo[3] <= 0;
|
||||
fifo[4] <= 0;
|
||||
fifo[5] <= 0;
|
||||
fifo[6] <= 0;
|
||||
fifo[7] <= 0;
|
||||
fifo[8] <= 0;
|
||||
fifo[9] <= 0;
|
||||
fifo[10] <= 0;
|
||||
fifo[11] <= 0;
|
||||
fifo[12] <= 0;
|
||||
fifo[13] <= 0;
|
||||
fifo[14] <= 0;
|
||||
fifo[15] <= 0;
|
||||
end
|
||||
else
|
||||
begin
|
||||
case ({push, pop})
|
||||
2'b10 : if (count<fifo_depth) // overrun condition
|
||||
begin
|
||||
top <= top_plus_1;
|
||||
fifo[top] <= data_in[2:0];
|
||||
count <= count + 5'd1;
|
||||
end
|
||||
2'b01 : if(count>0)
|
||||
begin
|
||||
fifo[bottom] <= 0;
|
||||
bottom <= bottom + 4'd1;
|
||||
count <= count - 5'd1;
|
||||
end
|
||||
2'b11 : begin
|
||||
bottom <= bottom + 4'd1;
|
||||
top <= top_plus_1;
|
||||
fifo[top] <= data_in[2:0];
|
||||
end
|
||||
default: ;
|
||||
endcase
|
||||
end
|
||||
end // always
|
||||
|
||||
always @(posedge clk or posedge wb_rst_i) // synchronous FIFO
|
||||
begin
|
||||
if (wb_rst_i)
|
||||
overrun <= 1'b0;
|
||||
else
|
||||
if(fifo_reset | reset_status)
|
||||
overrun <= 1'b0;
|
||||
else
|
||||
if(push & ~pop & (count==fifo_depth))
|
||||
overrun <= 1'b1;
|
||||
end // always
|
||||
|
||||
|
||||
// please note though that data_out is only valid one clock after pop signal
|
||||
assign data_out = {data8_out,fifo[bottom]};
|
||||
|
||||
// Additional logic for detection of error conditions (parity and framing) inside the FIFO
|
||||
// for the Line Status Register bit 7
|
||||
|
||||
wire [2:0] word0 = fifo[0];
|
||||
wire [2:0] word1 = fifo[1];
|
||||
wire [2:0] word2 = fifo[2];
|
||||
wire [2:0] word3 = fifo[3];
|
||||
wire [2:0] word4 = fifo[4];
|
||||
wire [2:0] word5 = fifo[5];
|
||||
wire [2:0] word6 = fifo[6];
|
||||
wire [2:0] word7 = fifo[7];
|
||||
|
||||
wire [2:0] word8 = fifo[8];
|
||||
wire [2:0] word9 = fifo[9];
|
||||
wire [2:0] word10 = fifo[10];
|
||||
wire [2:0] word11 = fifo[11];
|
||||
wire [2:0] word12 = fifo[12];
|
||||
wire [2:0] word13 = fifo[13];
|
||||
wire [2:0] word14 = fifo[14];
|
||||
wire [2:0] word15 = fifo[15];
|
||||
|
||||
// a 1 is returned if any of the error bits in the fifo is 1
|
||||
assign error_bit = |(word0[2:0] | word1[2:0] | word2[2:0] | word3[2:0] |
|
||||
word4[2:0] | word5[2:0] | word6[2:0] | word7[2:0] |
|
||||
word8[2:0] | word9[2:0] | word10[2:0] | word11[2:0] |
|
||||
word12[2:0] | word13[2:0] | word14[2:0] | word15[2:0] );
|
||||
|
||||
endmodule
|
||||
@ -0,0 +1,117 @@
|
||||
//////////////////////////////////////////////////////////////////////
|
||||
//// ////
|
||||
//// uart_sync_flops.v ////
|
||||
//// ////
|
||||
//// ////
|
||||
//// This file is part of the "UART 16550 compatible" project ////
|
||||
//// http://www.opencores.org/cores/uart16550/ ////
|
||||
//// ////
|
||||
//// Documentation related to this project: ////
|
||||
//// - http://www.opencores.org/cores/uart16550/ ////
|
||||
//// ////
|
||||
//// Projects compatibility: ////
|
||||
//// - WISHBONE ////
|
||||
//// RS232 Protocol ////
|
||||
//// 16550D uart (mostly supported) ////
|
||||
//// ////
|
||||
//// Overview (main Features): ////
|
||||
//// UART core receiver logic ////
|
||||
//// ////
|
||||
//// Known problems (limits): ////
|
||||
//// None known ////
|
||||
//// ////
|
||||
//// To Do: ////
|
||||
//// Thourough testing. ////
|
||||
//// ////
|
||||
//// Author(s): ////
|
||||
//// - Andrej Erzen (andreje@flextronics.si) ////
|
||||
//// - Tadej Markovic (tadejm@flextronics.si) ////
|
||||
//// ////
|
||||
//// Created: 2004/05/20 ////
|
||||
//// Last Updated: 2004/05/20 ////
|
||||
//// (See log for the revision history) ////
|
||||
//// ////
|
||||
//// ////
|
||||
//////////////////////////////////////////////////////////////////////
|
||||
//// ////
|
||||
//// Copyright (C) 2000, 2001 Authors ////
|
||||
//// ////
|
||||
//// This source file may be used and distributed without ////
|
||||
//// restriction provided that this copyright statement is not ////
|
||||
//// removed from the file and that any derivative work contains ////
|
||||
//// the original copyright notice and the associated disclaimer. ////
|
||||
//// ////
|
||||
//// This source file is free software; you can redistribute it ////
|
||||
//// and/or modify it under the terms of the GNU Lesser General ////
|
||||
//// Public License as published by the Free Software Foundation; ////
|
||||
//// either version 2.1 of the License, or (at your option) any ////
|
||||
//// later version. ////
|
||||
//// ////
|
||||
//// This source is distributed in the hope that it will be ////
|
||||
//// useful, but WITHOUT ANY WARRANTY; without even the implied ////
|
||||
//// warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR ////
|
||||
//// PURPOSE. See the GNU Lesser General Public License for more ////
|
||||
//// details. ////
|
||||
//// ////
|
||||
//// You should have received a copy of the GNU Lesser General ////
|
||||
//// Public License along with this source; if not, download it ////
|
||||
//// from http://www.opencores.org/lgpl.shtml ////
|
||||
//// ////
|
||||
//////////////////////////////////////////////////////////////////////
|
||||
//
|
||||
// CVS Revision History
|
||||
//
|
||||
// $Log: not supported by cvs2svn $
|
||||
//
|
||||
|
||||
module uart_sync_flops
|
||||
(
|
||||
// internal signals
|
||||
rst_i,
|
||||
clk_i,
|
||||
stage1_rst_i,
|
||||
stage1_clk_en_i,
|
||||
async_dat_i,
|
||||
sync_dat_o
|
||||
);
|
||||
|
||||
parameter width = 1;
|
||||
parameter init_value = 1'b0;
|
||||
|
||||
input rst_i; // reset input
|
||||
input clk_i; // clock input
|
||||
input stage1_rst_i; // synchronous reset for stage 1 FF
|
||||
input stage1_clk_en_i; // synchronous clock enable for stage 1 FF
|
||||
input [width-1:0] async_dat_i; // asynchronous data input
|
||||
output [width-1:0] sync_dat_o; // synchronous data output
|
||||
|
||||
|
||||
//
|
||||
// Interal signal declarations
|
||||
//
|
||||
|
||||
reg [width-1:0] sync_dat_o;
|
||||
reg [width-1:0] flop_0;
|
||||
|
||||
|
||||
// first stage
|
||||
always @ (posedge clk_i or posedge rst_i)
|
||||
begin
|
||||
if (rst_i)
|
||||
flop_0 <= {width{init_value}};
|
||||
else
|
||||
flop_0 <= async_dat_i;
|
||||
end
|
||||
|
||||
// second stage
|
||||
always @ (posedge clk_i or posedge rst_i)
|
||||
begin
|
||||
if (rst_i)
|
||||
sync_dat_o <= {width{init_value}};
|
||||
else if (stage1_rst_i)
|
||||
sync_dat_o <= {width{init_value}};
|
||||
else if (stage1_clk_en_i)
|
||||
sync_dat_o <= flop_0;
|
||||
end
|
||||
|
||||
endmodule
|
||||
@ -0,0 +1,239 @@
|
||||
//////////////////////////////////////////////////////////////////////
|
||||
//// ////
|
||||
//// uart_tfifo.v ////
|
||||
//// ////
|
||||
//// ////
|
||||
//// This file is part of the "UART 16550 compatible" project ////
|
||||
//// http://www.opencores.org/cores/uart16550/ ////
|
||||
//// ////
|
||||
//// Documentation related to this project: ////
|
||||
//// - http://www.opencores.org/cores/uart16550/ ////
|
||||
//// ////
|
||||
//// Projects compatibility: ////
|
||||
//// - WISHBONE ////
|
||||
//// RS232 Protocol ////
|
||||
//// 16550D uart (mostly supported) ////
|
||||
//// ////
|
||||
//// Overview (main Features): ////
|
||||
//// UART core transmitter FIFO ////
|
||||
//// ////
|
||||
//// To Do: ////
|
||||
//// Nothing. ////
|
||||
//// ////
|
||||
//// Author(s): ////
|
||||
//// - gorban@opencores.org ////
|
||||
//// - Jacob Gorban ////
|
||||
//// - Igor Mohor (igorm@opencores.org) ////
|
||||
//// ////
|
||||
//// Created: 2001/05/12 ////
|
||||
//// Last Updated: 2002/07/22 ////
|
||||
//// (See log for the revision history) ////
|
||||
//// ////
|
||||
//// ////
|
||||
//////////////////////////////////////////////////////////////////////
|
||||
//// ////
|
||||
//// Copyright (C) 2000, 2001 Authors ////
|
||||
//// ////
|
||||
//// This source file may be used and distributed without ////
|
||||
//// restriction provided that this copyright statement is not ////
|
||||
//// removed from the file and that any derivative work contains ////
|
||||
//// the original copyright notice and the associated disclaimer. ////
|
||||
//// ////
|
||||
//// This source file is free software; you can redistribute it ////
|
||||
//// and/or modify it under the terms of the GNU Lesser General ////
|
||||
//// Public License as published by the Free Software Foundation; ////
|
||||
//// either version 2.1 of the License, or (at your option) any ////
|
||||
//// later version. ////
|
||||
//// ////
|
||||
//// This source is distributed in the hope that it will be ////
|
||||
//// useful, but WITHOUT ANY WARRANTY; without even the implied ////
|
||||
//// warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR ////
|
||||
//// PURPOSE. See the GNU Lesser General Public License for more ////
|
||||
//// details. ////
|
||||
//// ////
|
||||
//// You should have received a copy of the GNU Lesser General ////
|
||||
//// Public License along with this source; if not, download it ////
|
||||
//// from http://www.opencores.org/lgpl.shtml ////
|
||||
//// ////
|
||||
//////////////////////////////////////////////////////////////////////
|
||||
//
|
||||
// CVS Revision History
|
||||
//
|
||||
// $Log: not supported by cvs2svn $
|
||||
// Revision 1.1 2002/07/22 23:02:23 gorban
|
||||
// Bug Fixes:
|
||||
// * Possible loss of sync and bad reception of stop bit on slow baud rates fixed.
|
||||
// Problem reported by Kenny.Tung.
|
||||
// * Bad (or lack of ) loopback handling fixed. Reported by Cherry Withers.
|
||||
//
|
||||
// Improvements:
|
||||
// * Made FIFO's as general inferrable memory where possible.
|
||||
// So on FPGA they should be inferred as RAM (Distributed RAM on Xilinx).
|
||||
// This saves about 1/3 of the Slice count and reduces P&R and synthesis times.
|
||||
//
|
||||
// * Added optional baudrate output (baud_o).
|
||||
// This is identical to BAUDOUT* signal on 16550 chip.
|
||||
// It outputs 16xbit_clock_rate - the divided clock.
|
||||
// It's disabled by default. Define UART_HAS_BAUDRATE_OUTPUT to use.
|
||||
//
|
||||
// Revision 1.16 2001/12/20 13:25:46 mohor
|
||||
// rx push changed to be only one cycle wide.
|
||||
//
|
||||
// Revision 1.15 2001/12/18 09:01:07 mohor
|
||||
// Bug that was entered in the last update fixed (rx state machine).
|
||||
//
|
||||
// Revision 1.14 2001/12/17 14:46:48 mohor
|
||||
// overrun signal was moved to separate block because many sequential lsr
|
||||
// reads were preventing data from being written to rx fifo.
|
||||
// underrun signal was not used and was removed from the project.
|
||||
//
|
||||
// Revision 1.13 2001/11/26 21:38:54 gorban
|
||||
// Lots of fixes:
|
||||
// Break condition wasn't handled correctly at all.
|
||||
// LSR bits could lose their values.
|
||||
// LSR value after reset was wrong.
|
||||
// Timing of THRE interrupt signal corrected.
|
||||
// LSR bit 0 timing corrected.
|
||||
//
|
||||
// Revision 1.12 2001/11/08 14:54:23 mohor
|
||||
// Comments in Slovene language deleted, few small fixes for better work of
|
||||
// old tools. IRQs need to be fix.
|
||||
//
|
||||
// Revision 1.11 2001/11/07 17:51:52 gorban
|
||||
// Heavily rewritten interrupt and LSR subsystems.
|
||||
// Many bugs hopefully squashed.
|
||||
//
|
||||
// Revision 1.10 2001/10/20 09:58:40 gorban
|
||||
// Small synopsis fixes
|
||||
//
|
||||
// Revision 1.9 2001/08/24 21:01:12 mohor
|
||||
// Things connected to parity changed.
|
||||
// Clock devider changed.
|
||||
//
|
||||
// Revision 1.8 2001/08/24 08:48:10 mohor
|
||||
// FIFO was not cleared after the data was read bug fixed.
|
||||
//
|
||||
// Revision 1.7 2001/08/23 16:05:05 mohor
|
||||
// Stop bit bug fixed.
|
||||
// Parity bug fixed.
|
||||
// WISHBONE read cycle bug fixed,
|
||||
// OE indicator (Overrun Error) bug fixed.
|
||||
// PE indicator (Parity Error) bug fixed.
|
||||
// Register read bug fixed.
|
||||
//
|
||||
// Revision 1.3 2001/05/31 20:08:01 gorban
|
||||
// FIFO changes and other corrections.
|
||||
//
|
||||
// Revision 1.3 2001/05/27 17:37:48 gorban
|
||||
// Fixed many bugs. Updated spec. Changed FIFO files structure. See CHANGES.txt file.
|
||||
//
|
||||
// Revision 1.2 2001/05/17 18:34:18 gorban
|
||||
// First 'stable' release. Should be sythesizable now. Also added new header.
|
||||
//
|
||||
// Revision 1.0 2001-05-17 21:27:12+02 jacob
|
||||
// Initial revision
|
||||
//
|
||||
//
|
||||
|
||||
`include "uart_defines.v"
|
||||
|
||||
module uart_tfifo (clk,
|
||||
wb_rst_i, data_in, data_out,
|
||||
// Control signals
|
||||
push, // push strobe, active high
|
||||
pop, // pop strobe, active high
|
||||
// status signals
|
||||
overrun,
|
||||
count,
|
||||
fifo_reset,
|
||||
reset_status
|
||||
);
|
||||
|
||||
|
||||
// FIFO parameters
|
||||
parameter fifo_width = `UART_FIFO_WIDTH;
|
||||
parameter fifo_depth = `UART_FIFO_DEPTH;
|
||||
parameter fifo_pointer_w = `UART_FIFO_POINTER_W;
|
||||
parameter fifo_counter_w = `UART_FIFO_COUNTER_W;
|
||||
|
||||
input clk;
|
||||
input wb_rst_i;
|
||||
input push;
|
||||
input pop;
|
||||
input [fifo_width-1:0] data_in;
|
||||
input fifo_reset;
|
||||
input reset_status;
|
||||
|
||||
output [fifo_width-1:0] data_out;
|
||||
output overrun;
|
||||
output [fifo_counter_w-1:0] count;
|
||||
|
||||
wire [fifo_width-1:0] data_out;
|
||||
|
||||
// FIFO pointers
|
||||
reg [fifo_pointer_w-1:0] top;
|
||||
reg [fifo_pointer_w-1:0] bottom;
|
||||
|
||||
reg [fifo_counter_w-1:0] count;
|
||||
reg overrun;
|
||||
wire [fifo_pointer_w-1:0] top_plus_1 = top + 4'd1;
|
||||
|
||||
raminfr #(fifo_pointer_w,fifo_width,fifo_depth) tfifo
|
||||
(.clk(clk),
|
||||
.we(push),
|
||||
.a(top),
|
||||
.dpra(bottom),
|
||||
.di(data_in),
|
||||
.dpo(data_out)
|
||||
);
|
||||
|
||||
|
||||
always @(posedge clk or posedge wb_rst_i) // synchronous FIFO
|
||||
begin
|
||||
if (wb_rst_i)
|
||||
begin
|
||||
top <= 0;
|
||||
bottom <= 0;
|
||||
count <= 0;
|
||||
end
|
||||
else
|
||||
if (fifo_reset) begin
|
||||
top <= 0;
|
||||
bottom <= 0;
|
||||
count <= 0;
|
||||
end
|
||||
else
|
||||
begin
|
||||
case ({push, pop})
|
||||
2'b10 : if (count<fifo_depth) // overrun condition
|
||||
begin
|
||||
top <= top_plus_1;
|
||||
count <= count + 5'd1;
|
||||
end
|
||||
2'b01 : if(count>0)
|
||||
begin
|
||||
bottom <= bottom + 4'd1;
|
||||
count <= count - 5'd1;
|
||||
end
|
||||
2'b11 : begin
|
||||
bottom <= bottom + 4'd1;
|
||||
top <= top_plus_1;
|
||||
end
|
||||
default: ;
|
||||
endcase
|
||||
end
|
||||
end // always
|
||||
|
||||
always @(posedge clk or posedge wb_rst_i) // synchronous FIFO
|
||||
begin
|
||||
if (wb_rst_i)
|
||||
overrun <= 1'b0;
|
||||
else
|
||||
if(fifo_reset | reset_status)
|
||||
overrun <= 1'b0;
|
||||
else
|
||||
if(push & (count==fifo_depth))
|
||||
overrun <= 1'b1;
|
||||
end // always
|
||||
|
||||
endmodule
|
||||
@ -0,0 +1,261 @@
|
||||
//////////////////////////////////////////////////////////////////////
|
||||
//// ////
|
||||
//// uart_top.v ////
|
||||
//// ////
|
||||
//// ////
|
||||
//// This file is part of the "UART 16550 compatible" project ////
|
||||
//// http://www.opencores.org/cores/uart16550/ ////
|
||||
//// ////
|
||||
//// Documentation related to this project: ////
|
||||
//// - http://www.opencores.org/cores/uart16550/ ////
|
||||
//// ////
|
||||
//// Projects compatibility: ////
|
||||
//// - WISHBONE ////
|
||||
//// RS232 Protocol ////
|
||||
//// 16550D uart (mostly supported) ////
|
||||
//// ////
|
||||
//// Overview (main Features): ////
|
||||
//// UART core top level. ////
|
||||
//// ////
|
||||
//// Known problems (limits): ////
|
||||
//// Note that transmitter and receiver instances are inside ////
|
||||
//// the uart_regs.v file. ////
|
||||
//// ////
|
||||
//// To Do: ////
|
||||
//// Nothing so far. ////
|
||||
//// ////
|
||||
//// Author(s): ////
|
||||
//// - gorban@opencores.org ////
|
||||
//// - Jacob Gorban ////
|
||||
//// - Igor Mohor (igorm@opencores.org) ////
|
||||
//// ////
|
||||
//// Created: 2001/05/12 ////
|
||||
//// Last Updated: 2001/05/17 ////
|
||||
//// (See log for the revision history) ////
|
||||
//// ////
|
||||
//// ////
|
||||
//////////////////////////////////////////////////////////////////////
|
||||
//// ////
|
||||
//// Copyright (C) 2000, 2001 Authors ////
|
||||
//// ////
|
||||
//// This source file may be used and distributed without ////
|
||||
//// restriction provided that this copyright statement is not ////
|
||||
//// removed from the file and that any derivative work contains ////
|
||||
//// the original copyright notice and the associated disclaimer. ////
|
||||
//// ////
|
||||
//// This source file is free software; you can redistribute it ////
|
||||
//// and/or modify it under the terms of the GNU Lesser General ////
|
||||
//// Public License as published by the Free Software Foundation; ////
|
||||
//// either version 2.1 of the License, or (at your option) any ////
|
||||
//// later version. ////
|
||||
//// ////
|
||||
//// This source is distributed in the hope that it will be ////
|
||||
//// useful, but WITHOUT ANY WARRANTY; without even the implied ////
|
||||
//// warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR ////
|
||||
//// PURPOSE. See the GNU Lesser General Public License for more ////
|
||||
//// details. ////
|
||||
//// ////
|
||||
//// You should have received a copy of the GNU Lesser General ////
|
||||
//// Public License along with this source; if not, download it ////
|
||||
//// from http://www.opencores.org/lgpl.shtml ////
|
||||
//// ////
|
||||
//////////////////////////////////////////////////////////////////////
|
||||
//
|
||||
// CVS Revision History
|
||||
//
|
||||
// $Log: not supported by cvs2svn $
|
||||
// Revision 1.18 2002/07/22 23:02:23 gorban
|
||||
// Bug Fixes:
|
||||
// * Possible loss of sync and bad reception of stop bit on slow baud rates fixed.
|
||||
// Problem reported by Kenny.Tung.
|
||||
// * Bad (or lack of ) loopback handling fixed. Reported by Cherry Withers.
|
||||
//
|
||||
// Improvements:
|
||||
// * Made FIFO's as general inferrable memory where possible.
|
||||
// So on FPGA they should be inferred as RAM (Distributed RAM on Xilinx).
|
||||
// This saves about 1/3 of the Slice count and reduces P&R and synthesis times.
|
||||
//
|
||||
// * Added optional baudrate output (baud_o).
|
||||
// This is identical to BAUDOUT* signal on 16550 chip.
|
||||
// It outputs 16xbit_clock_rate - the divided clock.
|
||||
// It's disabled by default. Define UART_HAS_BAUDRATE_OUTPUT to use.
|
||||
//
|
||||
// Revision 1.17 2001/12/19 08:40:03 mohor
|
||||
// Warnings fixed (unused signals removed).
|
||||
//
|
||||
// Revision 1.16 2001/12/06 14:51:04 gorban
|
||||
// Bug in LSR[0] is fixed.
|
||||
// All WISHBONE signals are now sampled, so another wait-state is introduced on all transfers.
|
||||
//
|
||||
// Revision 1.15 2001/12/03 21:44:29 gorban
|
||||
// Updated specification documentation.
|
||||
// Added full 32-bit data bus interface, now as default.
|
||||
// Address is 5-bit wide in 32-bit data bus mode.
|
||||
// Added wb_sel_i input to the core. It's used in the 32-bit mode.
|
||||
// Added debug interface with two 32-bit read-only registers in 32-bit mode.
|
||||
// Bits 5 and 6 of LSR are now only cleared on TX FIFO write.
|
||||
// My small test bench is modified to work with 32-bit mode.
|
||||
//
|
||||
// Revision 1.14 2001/11/07 17:51:52 gorban
|
||||
// Heavily rewritten interrupt and LSR subsystems.
|
||||
// Many bugs hopefully squashed.
|
||||
//
|
||||
// Revision 1.13 2001/10/20 09:58:40 gorban
|
||||
// Small synopsis fixes
|
||||
//
|
||||
// Revision 1.12 2001/08/25 15:46:19 gorban
|
||||
// Modified port names again
|
||||
//
|
||||
// Revision 1.11 2001/08/24 21:01:12 mohor
|
||||
// Things connected to parity changed.
|
||||
// Clock devider changed.
|
||||
//
|
||||
// Revision 1.10 2001/08/23 16:05:05 mohor
|
||||
// Stop bit bug fixed.
|
||||
// Parity bug fixed.
|
||||
// WISHBONE read cycle bug fixed,
|
||||
// OE indicator (Overrun Error) bug fixed.
|
||||
// PE indicator (Parity Error) bug fixed.
|
||||
// Register read bug fixed.
|
||||
//
|
||||
// Revision 1.4 2001/05/31 20:08:01 gorban
|
||||
// FIFO changes and other corrections.
|
||||
//
|
||||
// Revision 1.3 2001/05/21 19:12:02 gorban
|
||||
// Corrected some Linter messages.
|
||||
//
|
||||
// Revision 1.2 2001/05/17 18:34:18 gorban
|
||||
// First 'stable' release. Should be sythesizable now. Also added new header.
|
||||
//
|
||||
// Revision 1.0 2001-05-17 21:27:12+02 jacob
|
||||
// Initial revision
|
||||
//
|
||||
//
|
||||
|
||||
`include "uart_defines.v"
|
||||
|
||||
module uart_top (
|
||||
wb_clk_i,
|
||||
|
||||
// Wishbone signals
|
||||
wb_rst_i, wb_adr_i, wb_dat_i, wb_dat_o, wb_we_i, wb_stb_i, wb_cyc_i, wb_ack_o, wb_sel_i,
|
||||
int_o, // interrupt request
|
||||
|
||||
// UART signals
|
||||
// serial input/output
|
||||
stx_pad_o, srx_pad_i,
|
||||
|
||||
// modem signals
|
||||
rts_pad_o, cts_pad_i, dtr_pad_o, dsr_pad_i, ri_pad_i, dcd_pad_i
|
||||
`ifdef UART_HAS_BAUDRATE_OUTPUT
|
||||
, baud_o
|
||||
`endif
|
||||
);
|
||||
parameter SIM = 0;
|
||||
parameter debug = 0;
|
||||
|
||||
input wb_clk_i;
|
||||
|
||||
// WISHBONE interface
|
||||
input wb_rst_i;
|
||||
input [2:0] wb_adr_i;
|
||||
input [7:0] wb_dat_i;
|
||||
output [7:0] wb_dat_o;
|
||||
input wb_we_i;
|
||||
input wb_stb_i;
|
||||
input wb_cyc_i;
|
||||
input [3:0] wb_sel_i;
|
||||
output wb_ack_o;
|
||||
output int_o;
|
||||
|
||||
// UART signals
|
||||
input srx_pad_i;
|
||||
output stx_pad_o;
|
||||
output rts_pad_o;
|
||||
input cts_pad_i;
|
||||
output dtr_pad_o;
|
||||
input dsr_pad_i;
|
||||
input ri_pad_i;
|
||||
input dcd_pad_i;
|
||||
|
||||
// optional baudrate output
|
||||
`ifdef UART_HAS_BAUDRATE_OUTPUT
|
||||
output baud_o;
|
||||
`endif
|
||||
|
||||
|
||||
wire stx_pad_o;
|
||||
wire rts_pad_o;
|
||||
wire dtr_pad_o;
|
||||
|
||||
wire [2:0] wb_adr_i;
|
||||
wire [7:0] wb_dat_i;
|
||||
wire [7:0] wb_dat_o;
|
||||
|
||||
wire [7:0] wb_dat8_i; // 8-bit internal data input
|
||||
wire [7:0] wb_dat8_o; // 8-bit internal data output
|
||||
wire [31:0] wb_dat32_o; // debug interface 32-bit output
|
||||
wire [3:0] wb_sel_i; // WISHBONE select signal
|
||||
wire [2:0] wb_adr_int;
|
||||
wire we_o; // Write enable for registers
|
||||
wire re_o; // Read enable for registers
|
||||
//
|
||||
// MODULE INSTANCES
|
||||
//
|
||||
|
||||
//// WISHBONE interface module
|
||||
uart_wb wb_interface(
|
||||
.clk( wb_clk_i ),
|
||||
.wb_rst_i( wb_rst_i ),
|
||||
.wb_dat_i(wb_dat_i),
|
||||
.wb_dat_o(wb_dat_o),
|
||||
.wb_dat8_i(wb_dat8_i),
|
||||
.wb_dat8_o(wb_dat8_o),
|
||||
.wb_dat32_o(32'b0),
|
||||
.wb_sel_i(4'b0),
|
||||
.wb_we_i( wb_we_i ),
|
||||
.wb_stb_i( wb_stb_i ),
|
||||
.wb_cyc_i( wb_cyc_i ),
|
||||
.wb_ack_o( wb_ack_o ),
|
||||
.wb_adr_i(wb_adr_i),
|
||||
.wb_adr_int(wb_adr_int),
|
||||
.we_o( we_o ),
|
||||
.re_o(re_o)
|
||||
);
|
||||
|
||||
// Registers
|
||||
uart_regs #(.SIM (SIM)) regs(
|
||||
.clk( wb_clk_i ),
|
||||
.wb_rst_i( wb_rst_i ),
|
||||
.wb_addr_i( wb_adr_int ),
|
||||
.wb_dat_i( wb_dat8_i ),
|
||||
.wb_dat_o( wb_dat8_o ),
|
||||
.wb_we_i( we_o ),
|
||||
.wb_re_i(re_o),
|
||||
.modem_inputs( {cts_pad_i, dsr_pad_i,
|
||||
ri_pad_i, dcd_pad_i} ),
|
||||
.stx_pad_o( stx_pad_o ),
|
||||
.srx_pad_i( srx_pad_i ),
|
||||
.rts_pad_o( rts_pad_o ),
|
||||
.dtr_pad_o( dtr_pad_o ),
|
||||
.int_o( int_o )
|
||||
`ifdef UART_HAS_BAUDRATE_OUTPUT
|
||||
, .baud_o(baud_o)
|
||||
`endif
|
||||
|
||||
);
|
||||
|
||||
initial
|
||||
begin
|
||||
if(debug) begin
|
||||
`ifdef UART_HAS_BAUDRATE_OUTPUT
|
||||
$display("(%m) UART INFO: Has baudrate output\n");
|
||||
`else
|
||||
$display("(%m) UART INFO: Doesn't have baudrate output\n");
|
||||
`endif
|
||||
end
|
||||
end
|
||||
|
||||
endmodule
|
||||
|
||||
|
||||
@ -0,0 +1,354 @@
|
||||
//////////////////////////////////////////////////////////////////////
|
||||
//// ////
|
||||
//// uart_transmitter.v ////
|
||||
//// ////
|
||||
//// ////
|
||||
//// This file is part of the "UART 16550 compatible" project ////
|
||||
//// http://www.opencores.org/cores/uart16550/ ////
|
||||
//// ////
|
||||
//// Documentation related to this project: ////
|
||||
//// - http://www.opencores.org/cores/uart16550/ ////
|
||||
//// ////
|
||||
//// Projects compatibility: ////
|
||||
//// - WISHBONE ////
|
||||
//// RS232 Protocol ////
|
||||
//// 16550D uart (mostly supported) ////
|
||||
//// ////
|
||||
//// Overview (main Features): ////
|
||||
//// UART core transmitter logic ////
|
||||
//// ////
|
||||
//// Known problems (limits): ////
|
||||
//// None known ////
|
||||
//// ////
|
||||
//// To Do: ////
|
||||
//// Thourough testing. ////
|
||||
//// ////
|
||||
//// Author(s): ////
|
||||
//// - gorban@opencores.org ////
|
||||
//// - Jacob Gorban ////
|
||||
//// - Igor Mohor (igorm@opencores.org) ////
|
||||
//// ////
|
||||
//// Created: 2001/05/12 ////
|
||||
//// Last Updated: 2001/05/17 ////
|
||||
//// (See log for the revision history) ////
|
||||
//// ////
|
||||
//// ////
|
||||
//////////////////////////////////////////////////////////////////////
|
||||
//// ////
|
||||
//// Copyright (C) 2000, 2001 Authors ////
|
||||
//// ////
|
||||
//// This source file may be used and distributed without ////
|
||||
//// restriction provided that this copyright statement is not ////
|
||||
//// removed from the file and that any derivative work contains ////
|
||||
//// the original copyright notice and the associated disclaimer. ////
|
||||
//// ////
|
||||
//// This source file is free software; you can redistribute it ////
|
||||
//// and/or modify it under the terms of the GNU Lesser General ////
|
||||
//// Public License as published by the Free Software Foundation; ////
|
||||
//// either version 2.1 of the License, or (at your option) any ////
|
||||
//// later version. ////
|
||||
//// ////
|
||||
//// This source is distributed in the hope that it will be ////
|
||||
//// useful, but WITHOUT ANY WARRANTY; without even the implied ////
|
||||
//// warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR ////
|
||||
//// PURPOSE. See the GNU Lesser General Public License for more ////
|
||||
//// details. ////
|
||||
//// ////
|
||||
//// You should have received a copy of the GNU Lesser General ////
|
||||
//// Public License along with this source; if not, download it ////
|
||||
//// from http://www.opencores.org/lgpl.shtml ////
|
||||
//// ////
|
||||
//////////////////////////////////////////////////////////////////////
|
||||
//
|
||||
// CVS Revision History
|
||||
//
|
||||
// $Log: not supported by cvs2svn $
|
||||
// Revision 1.18 2002/07/22 23:02:23 gorban
|
||||
// Bug Fixes:
|
||||
// * Possible loss of sync and bad reception of stop bit on slow baud rates fixed.
|
||||
// Problem reported by Kenny.Tung.
|
||||
// * Bad (or lack of ) loopback handling fixed. Reported by Cherry Withers.
|
||||
//
|
||||
// Improvements:
|
||||
// * Made FIFO's as general inferrable memory where possible.
|
||||
// So on FPGA they should be inferred as RAM (Distributed RAM on Xilinx).
|
||||
// This saves about 1/3 of the Slice count and reduces P&R and synthesis times.
|
||||
//
|
||||
// * Added optional baudrate output (baud_o).
|
||||
// This is identical to BAUDOUT* signal on 16550 chip.
|
||||
// It outputs 16xbit_clock_rate - the divided clock.
|
||||
// It's disabled by default. Define UART_HAS_BAUDRATE_OUTPUT to use.
|
||||
//
|
||||
// Revision 1.16 2002/01/08 11:29:40 mohor
|
||||
// tf_pop was too wide. Now it is only 1 clk cycle width.
|
||||
//
|
||||
// Revision 1.15 2001/12/17 14:46:48 mohor
|
||||
// overrun signal was moved to separate block because many sequential lsr
|
||||
// reads were preventing data from being written to rx fifo.
|
||||
// underrun signal was not used and was removed from the project.
|
||||
//
|
||||
// Revision 1.14 2001/12/03 21:44:29 gorban
|
||||
// Updated specification documentation.
|
||||
// Added full 32-bit data bus interface, now as default.
|
||||
// Address is 5-bit wide in 32-bit data bus mode.
|
||||
// Added wb_sel_i input to the core. It's used in the 32-bit mode.
|
||||
// Added debug interface with two 32-bit read-only registers in 32-bit mode.
|
||||
// Bits 5 and 6 of LSR are now only cleared on TX FIFO write.
|
||||
// My small test bench is modified to work with 32-bit mode.
|
||||
//
|
||||
// Revision 1.13 2001/11/08 14:54:23 mohor
|
||||
// Comments in Slovene language deleted, few small fixes for better work of
|
||||
// old tools. IRQs need to be fix.
|
||||
//
|
||||
// Revision 1.12 2001/11/07 17:51:52 gorban
|
||||
// Heavily rewritten interrupt and LSR subsystems.
|
||||
// Many bugs hopefully squashed.
|
||||
//
|
||||
// Revision 1.11 2001/10/29 17:00:46 gorban
|
||||
// fixed parity sending and tx_fifo resets over- and underrun
|
||||
//
|
||||
// Revision 1.10 2001/10/20 09:58:40 gorban
|
||||
// Small synopsis fixes
|
||||
//
|
||||
// Revision 1.9 2001/08/24 21:01:12 mohor
|
||||
// Things connected to parity changed.
|
||||
// Clock devider changed.
|
||||
//
|
||||
// Revision 1.8 2001/08/23 16:05:05 mohor
|
||||
// Stop bit bug fixed.
|
||||
// Parity bug fixed.
|
||||
// WISHBONE read cycle bug fixed,
|
||||
// OE indicator (Overrun Error) bug fixed.
|
||||
// PE indicator (Parity Error) bug fixed.
|
||||
// Register read bug fixed.
|
||||
//
|
||||
// Revision 1.6 2001/06/23 11:21:48 gorban
|
||||
// DL made 16-bit long. Fixed transmission/reception bugs.
|
||||
//
|
||||
// Revision 1.5 2001/06/02 14:28:14 gorban
|
||||
// Fixed receiver and transmitter. Major bug fixed.
|
||||
//
|
||||
// Revision 1.4 2001/05/31 20:08:01 gorban
|
||||
// FIFO changes and other corrections.
|
||||
//
|
||||
// Revision 1.3 2001/05/27 17:37:49 gorban
|
||||
// Fixed many bugs. Updated spec. Changed FIFO files structure. See CHANGES.txt file.
|
||||
//
|
||||
// Revision 1.2 2001/05/21 19:12:02 gorban
|
||||
// Corrected some Linter messages.
|
||||
//
|
||||
// Revision 1.1 2001/05/17 18:34:18 gorban
|
||||
// First 'stable' release. Should be sythesizable now. Also added new header.
|
||||
//
|
||||
// Revision 1.0 2001-05-17 21:27:12+02 jacob
|
||||
// Initial revision
|
||||
//
|
||||
//
|
||||
|
||||
`include "uart_defines.v"
|
||||
|
||||
module uart_transmitter
|
||||
#(parameter SIM = 0)
|
||||
(clk, wb_rst_i, lcr, tf_push, wb_dat_i, enable, stx_pad_o, tstate, tf_count, tx_reset, lsr_mask);
|
||||
|
||||
input clk;
|
||||
input wb_rst_i;
|
||||
input [7:0] lcr;
|
||||
input tf_push;
|
||||
input [7:0] wb_dat_i;
|
||||
input enable;
|
||||
input tx_reset;
|
||||
input lsr_mask; //reset of fifo
|
||||
output stx_pad_o;
|
||||
output [2:0] tstate;
|
||||
output [`UART_FIFO_COUNTER_W-1:0] tf_count;
|
||||
|
||||
reg [2:0] tstate;
|
||||
reg [4:0] counter;
|
||||
reg [2:0] bit_counter; // counts the bits to be sent
|
||||
reg [6:0] shift_out; // output shift register
|
||||
reg stx_o_tmp;
|
||||
reg parity_xor; // parity of the word
|
||||
reg tf_pop;
|
||||
reg bit_out;
|
||||
|
||||
// TX FIFO instance
|
||||
//
|
||||
// Transmitter FIFO signals
|
||||
wire [`UART_FIFO_WIDTH-1:0] tf_data_in;
|
||||
wire [`UART_FIFO_WIDTH-1:0] tf_data_out;
|
||||
wire tf_push;
|
||||
wire tf_overrun;
|
||||
wire [`UART_FIFO_COUNTER_W-1:0] tf_count;
|
||||
|
||||
assign tf_data_in = wb_dat_i;
|
||||
|
||||
uart_tfifo fifo_tx( // error bit signal is not used in transmitter FIFO
|
||||
.clk( clk ),
|
||||
.wb_rst_i( wb_rst_i ),
|
||||
.data_in( tf_data_in ),
|
||||
.data_out( tf_data_out ),
|
||||
.push( tf_push ),
|
||||
.pop( tf_pop ),
|
||||
.overrun( tf_overrun ),
|
||||
.count( tf_count ),
|
||||
.fifo_reset( tx_reset ),
|
||||
.reset_status(lsr_mask)
|
||||
);
|
||||
|
||||
// TRANSMITTER FINAL STATE MACHINE
|
||||
|
||||
localparam s_idle = 3'd0;
|
||||
localparam s_send_start = 3'd1;
|
||||
localparam s_send_byte = 3'd2;
|
||||
localparam s_send_parity = 3'd3;
|
||||
localparam s_send_stop = 3'd4;
|
||||
localparam s_pop_byte = 3'd5;
|
||||
|
||||
always @(posedge clk or posedge wb_rst_i)
|
||||
begin
|
||||
if (wb_rst_i)
|
||||
begin
|
||||
tstate <= s_idle;
|
||||
stx_o_tmp <= 1'b1;
|
||||
counter <= 5'b0;
|
||||
shift_out <= 7'b0;
|
||||
bit_out <= 1'b0;
|
||||
parity_xor <= 1'b0;
|
||||
tf_pop <= 1'b0;
|
||||
bit_counter <= 3'b0;
|
||||
end
|
||||
else
|
||||
if (enable | SIM)
|
||||
begin
|
||||
case (tstate)
|
||||
s_idle : if (~|tf_count) // if tf_count==0
|
||||
begin
|
||||
tstate <= s_idle;
|
||||
stx_o_tmp <= 1'b1;
|
||||
end
|
||||
else
|
||||
begin
|
||||
tf_pop <= 1'b0;
|
||||
stx_o_tmp <= 1'b1;
|
||||
tstate <= s_pop_byte;
|
||||
end
|
||||
s_pop_byte : begin
|
||||
tf_pop <= 1'b1;
|
||||
case (lcr[/*`UART_LC_BITS*/1:0]) // number of bits in a word
|
||||
2'b00 : begin
|
||||
bit_counter <= 3'b100;
|
||||
parity_xor <= ^tf_data_out[4:0];
|
||||
end
|
||||
2'b01 : begin
|
||||
bit_counter <= 3'b101;
|
||||
parity_xor <= ^tf_data_out[5:0];
|
||||
end
|
||||
2'b10 : begin
|
||||
bit_counter <= 3'b110;
|
||||
parity_xor <= ^tf_data_out[6:0];
|
||||
end
|
||||
2'b11 : begin
|
||||
bit_counter <= 3'b111;
|
||||
parity_xor <= ^tf_data_out[7:0];
|
||||
end
|
||||
endcase
|
||||
{shift_out[6:0], bit_out} <= tf_data_out;
|
||||
tstate <= s_send_start;
|
||||
end
|
||||
s_send_start : begin
|
||||
tf_pop <= 1'b0;
|
||||
if (~|counter)
|
||||
counter <= 5'b01111;
|
||||
else
|
||||
if (counter == 5'b00001)
|
||||
begin
|
||||
counter <= 0;
|
||||
tstate <= s_send_byte;
|
||||
end
|
||||
else
|
||||
counter <= counter - 5'd1;
|
||||
stx_o_tmp <= 1'b0;
|
||||
if (SIM) begin
|
||||
tstate <= s_idle;
|
||||
$write("%c", tf_data_out);
|
||||
$fflush(32'h80000001);
|
||||
end
|
||||
end
|
||||
s_send_byte : begin
|
||||
if (~|counter)
|
||||
counter <= 5'b01111;
|
||||
else
|
||||
if (counter == 5'b00001)
|
||||
begin
|
||||
if (bit_counter > 3'b0)
|
||||
begin
|
||||
bit_counter <= bit_counter - 3'd1;
|
||||
{shift_out[5:0],bit_out } <= {shift_out[6:1], shift_out[0]};
|
||||
tstate <= s_send_byte;
|
||||
end
|
||||
else // end of byte
|
||||
if (~lcr[`UART_LC_PE])
|
||||
begin
|
||||
tstate <= s_send_stop;
|
||||
end
|
||||
else
|
||||
begin
|
||||
case ({lcr[`UART_LC_EP],lcr[`UART_LC_SP]})
|
||||
2'b00: bit_out <= ~parity_xor;
|
||||
2'b01: bit_out <= 1'b1;
|
||||
2'b10: bit_out <= parity_xor;
|
||||
2'b11: bit_out <= 1'b0;
|
||||
endcase
|
||||
tstate <= s_send_parity;
|
||||
end
|
||||
counter <= 0;
|
||||
end
|
||||
else
|
||||
counter <= counter - 5'd1;
|
||||
stx_o_tmp <= bit_out; // set output pin
|
||||
end
|
||||
s_send_parity : begin
|
||||
if (~|counter)
|
||||
counter <= 5'b01111;
|
||||
else
|
||||
if (counter == 5'b00001)
|
||||
begin
|
||||
counter <= 5'd0;
|
||||
tstate <= s_send_stop;
|
||||
end
|
||||
else
|
||||
counter <= counter - 5'd1;
|
||||
stx_o_tmp <= bit_out;
|
||||
end
|
||||
s_send_stop : begin
|
||||
if (~|counter)
|
||||
begin
|
||||
casez ({lcr[`UART_LC_SB],lcr[`UART_LC_BITS]})
|
||||
3'b0??: counter <= 5'b01101; // 1 stop bit ok igor
|
||||
3'b100: counter <= 5'b10101; // 1.5 stop bit
|
||||
default: counter <= 5'b11101; // 2 stop bits
|
||||
endcase
|
||||
end
|
||||
else
|
||||
if (counter == 5'b00001)
|
||||
begin
|
||||
counter <= 0;
|
||||
tstate <= s_idle;
|
||||
end
|
||||
else
|
||||
counter <= counter - 5'd1;
|
||||
stx_o_tmp <= 1'b1;
|
||||
end
|
||||
|
||||
default : // should never get here
|
||||
tstate <= s_idle;
|
||||
endcase
|
||||
end // end if enable
|
||||
else
|
||||
tf_pop <= 1'b0; // tf_pop must be 1 cycle width
|
||||
end // transmitter logic
|
||||
|
||||
assign stx_pad_o = lcr[`UART_LC_BC] ? 1'b0 : stx_o_tmp; // Break condition
|
||||
|
||||
endmodule
|
||||
@ -0,0 +1,258 @@
|
||||
//////////////////////////////////////////////////////////////////////
|
||||
//// ////
|
||||
//// uart_wb.v ////
|
||||
//// ////
|
||||
//// ////
|
||||
//// This file is part of the "UART 16550 compatible" project ////
|
||||
//// http://www.opencores.org/cores/uart16550/ ////
|
||||
//// ////
|
||||
//// Documentation related to this project: ////
|
||||
//// - http://www.opencores.org/cores/uart16550/ ////
|
||||
//// ////
|
||||
//// Projects compatibility: ////
|
||||
//// - WISHBONE ////
|
||||
//// RS232 Protocol ////
|
||||
//// 16550D uart (mostly supported) ////
|
||||
//// ////
|
||||
//// Overview (main Features): ////
|
||||
//// UART core WISHBONE interface. ////
|
||||
//// ////
|
||||
//// Known problems (limits): ////
|
||||
//// Inserts one wait state on all transfers. ////
|
||||
//// Note affected signals and the way they are affected. ////
|
||||
//// ////
|
||||
//// To Do: ////
|
||||
//// Nothing. ////
|
||||
//// ////
|
||||
//// Author(s): ////
|
||||
//// - gorban@opencores.org ////
|
||||
//// - Jacob Gorban ////
|
||||
//// - Igor Mohor (igorm@opencores.org) ////
|
||||
//// ////
|
||||
//// Created: 2001/05/12 ////
|
||||
//// Last Updated: 2001/05/17 ////
|
||||
//// (See log for the revision history) ////
|
||||
//// ////
|
||||
//// ////
|
||||
//////////////////////////////////////////////////////////////////////
|
||||
//// ////
|
||||
//// Copyright (C) 2000, 2001 Authors ////
|
||||
//// ////
|
||||
//// This source file may be used and distributed without ////
|
||||
//// restriction provided that this copyright statement is not ////
|
||||
//// removed from the file and that any derivative work contains ////
|
||||
//// the original copyright notice and the associated disclaimer. ////
|
||||
//// ////
|
||||
//// This source file is free software; you can redistribute it ////
|
||||
//// and/or modify it under the terms of the GNU Lesser General ////
|
||||
//// Public License as published by the Free Software Foundation; ////
|
||||
//// either version 2.1 of the License, or (at your option) any ////
|
||||
//// later version. ////
|
||||
//// ////
|
||||
//// This source is distributed in the hope that it will be ////
|
||||
//// useful, but WITHOUT ANY WARRANTY; without even the implied ////
|
||||
//// warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR ////
|
||||
//// PURPOSE. See the GNU Lesser General Public License for more ////
|
||||
//// details. ////
|
||||
//// ////
|
||||
//// You should have received a copy of the GNU Lesser General ////
|
||||
//// Public License along with this source; if not, download it ////
|
||||
//// from http://www.opencores.org/lgpl.shtml ////
|
||||
//// ////
|
||||
//////////////////////////////////////////////////////////////////////
|
||||
//
|
||||
// CVS Revision History
|
||||
//
|
||||
// $Log: not supported by cvs2svn $
|
||||
// Revision 1.16 2002/07/29 21:16:18 gorban
|
||||
// The uart_defines.v file is included again in sources.
|
||||
//
|
||||
// Revision 1.15 2002/07/22 23:02:23 gorban
|
||||
// Bug Fixes:
|
||||
// * Possible loss of sync and bad reception of stop bit on slow baud rates fixed.
|
||||
// Problem reported by Kenny.Tung.
|
||||
// * Bad (or lack of ) loopback handling fixed. Reported by Cherry Withers.
|
||||
//
|
||||
// Improvements:
|
||||
// * Made FIFO's as general inferrable memory where possible.
|
||||
// So on FPGA they should be inferred as RAM (Distributed RAM on Xilinx).
|
||||
// This saves about 1/3 of the Slice count and reduces P&R and synthesis times.
|
||||
//
|
||||
// * Added optional baudrate output (baud_o).
|
||||
// This is identical to BAUDOUT* signal on 16550 chip.
|
||||
// It outputs 16xbit_clock_rate - the divided clock.
|
||||
// It's disabled by default. Define UART_HAS_BAUDRATE_OUTPUT to use.
|
||||
//
|
||||
// Revision 1.12 2001/12/19 08:03:34 mohor
|
||||
// Warnings cleared.
|
||||
//
|
||||
// Revision 1.11 2001/12/06 14:51:04 gorban
|
||||
// Bug in LSR[0] is fixed.
|
||||
// All WISHBONE signals are now sampled, so another wait-state is introduced on all transfers.
|
||||
//
|
||||
// Revision 1.10 2001/12/03 21:44:29 gorban
|
||||
// Updated specification documentation.
|
||||
// Added full 32-bit data bus interface, now as default.
|
||||
// Address is 5-bit wide in 32-bit data bus mode.
|
||||
// Added wb_sel_i input to the core. It's used in the 32-bit mode.
|
||||
// Added debug interface with two 32-bit read-only registers in 32-bit mode.
|
||||
// Bits 5 and 6 of LSR are now only cleared on TX FIFO write.
|
||||
// My small test bench is modified to work with 32-bit mode.
|
||||
//
|
||||
// Revision 1.9 2001/10/20 09:58:40 gorban
|
||||
// Small synopsis fixes
|
||||
//
|
||||
// Revision 1.8 2001/08/24 21:01:12 mohor
|
||||
// Things connected to parity changed.
|
||||
// Clock devider changed.
|
||||
//
|
||||
// Revision 1.7 2001/08/23 16:05:05 mohor
|
||||
// Stop bit bug fixed.
|
||||
// Parity bug fixed.
|
||||
// WISHBONE read cycle bug fixed,
|
||||
// OE indicator (Overrun Error) bug fixed.
|
||||
// PE indicator (Parity Error) bug fixed.
|
||||
// Register read bug fixed.
|
||||
//
|
||||
// Revision 1.4 2001/05/31 20:08:01 gorban
|
||||
// FIFO changes and other corrections.
|
||||
//
|
||||
// Revision 1.3 2001/05/21 19:12:01 gorban
|
||||
// Corrected some Linter messages.
|
||||
//
|
||||
// Revision 1.2 2001/05/17 18:34:18 gorban
|
||||
// First 'stable' release. Should be sythesizable now. Also added new header.
|
||||
//
|
||||
// Revision 1.0 2001-05-17 21:27:13+02 jacob
|
||||
// Initial revision
|
||||
//
|
||||
//
|
||||
|
||||
// UART core WISHBONE interface
|
||||
//
|
||||
// Author: Jacob Gorban (jacob.gorban@flextronicssemi.com)
|
||||
// Company: Flextronics Semiconductor
|
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//
|
||||
|
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`include "uart_defines.v"
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|
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module uart_wb (clk, wb_rst_i,
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wb_we_i, wb_stb_i, wb_cyc_i, wb_ack_o, wb_adr_i,
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wb_adr_int, wb_dat_i, wb_dat_o, wb_dat8_i, wb_dat8_o, wb_dat32_o, wb_sel_i,
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we_o, re_o // Write and read enable output for the core
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);
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input clk;
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// WISHBONE interface
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input wb_rst_i;
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input wb_we_i;
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input wb_stb_i;
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input wb_cyc_i;
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input [3:0] wb_sel_i;
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input [2:0] wb_adr_i; //WISHBONE address line
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input [7:0] wb_dat_i; //input WISHBONE bus
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output [7:0] wb_dat_o;
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reg [7:0] wb_dat_o;
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wire [7:0] wb_dat_i;
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reg [7:0] wb_dat_is;
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output [2:0] wb_adr_int; // internal signal for address bus
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input [7:0] wb_dat8_o; // internal 8 bit output to be put into wb_dat_o
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output [7:0] wb_dat8_i;
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input [31:0] wb_dat32_o; // 32 bit data output (for debug interface)
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output wb_ack_o;
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output we_o;
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||||
output re_o;
|
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|
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wire we_o;
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||||
reg wb_ack_o;
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||||
reg [7:0] wb_dat8_i;
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||||
wire [7:0] wb_dat8_o;
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||||
wire [2:0] wb_adr_int; // internal signal for address bus
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||||
reg [2:0] wb_adr_is;
|
||||
reg wb_we_is;
|
||||
reg wb_cyc_is;
|
||||
reg wb_stb_is;
|
||||
wire [3:0] wb_sel_i;
|
||||
reg wre ;// timing control signal for write or read enable
|
||||
|
||||
// wb_ack_o FSM
|
||||
reg [1:0] wbstate;
|
||||
always @(posedge clk or posedge wb_rst_i)
|
||||
if (wb_rst_i) begin
|
||||
wb_ack_o <= 1'b0;
|
||||
wbstate <= 0;
|
||||
wre <= 1'b1;
|
||||
end else
|
||||
case (wbstate)
|
||||
0: begin
|
||||
if (wb_stb_is & wb_cyc_is) begin
|
||||
wre <= 0;
|
||||
wbstate <= 1;
|
||||
wb_ack_o <= 1;
|
||||
end else begin
|
||||
wre <= 1;
|
||||
wb_ack_o <= 0;
|
||||
end
|
||||
end
|
||||
1: begin
|
||||
wb_ack_o <= 0;
|
||||
wbstate <= 2;
|
||||
wre <= 0;
|
||||
end
|
||||
2: begin
|
||||
wb_ack_o <= 0;
|
||||
wbstate <= 3;
|
||||
wre <= 0;
|
||||
end
|
||||
3: begin
|
||||
wb_ack_o <= 0;
|
||||
wbstate <= 0;
|
||||
wre <= 1;
|
||||
end
|
||||
endcase
|
||||
|
||||
assign we_o = wb_we_is & wb_stb_is & wb_cyc_is & wre ; //WE for registers
|
||||
assign re_o = ~wb_we_is & wb_stb_is & wb_cyc_is & wre ; //RE for registers
|
||||
|
||||
// Sample input signals
|
||||
always @(posedge clk or posedge wb_rst_i)
|
||||
if (wb_rst_i) begin
|
||||
wb_adr_is <= 0;
|
||||
wb_we_is <= 0;
|
||||
wb_cyc_is <= 0;
|
||||
wb_stb_is <= 0;
|
||||
wb_dat_is <= 0;
|
||||
end else begin
|
||||
wb_adr_is <= wb_adr_i;
|
||||
wb_we_is <= wb_we_i;
|
||||
wb_cyc_is <= wb_cyc_i;
|
||||
wb_stb_is <= wb_stb_i;
|
||||
wb_dat_is <= wb_dat_i;
|
||||
end
|
||||
|
||||
always @(posedge clk or posedge wb_rst_i)
|
||||
if (wb_rst_i)
|
||||
wb_dat_o <= 0;
|
||||
else
|
||||
wb_dat_o <= wb_dat8_o;
|
||||
|
||||
always @(wb_dat_is)
|
||||
wb_dat8_i = wb_dat_is;
|
||||
|
||||
assign wb_adr_int = wb_adr_is;
|
||||
|
||||
|
||||
endmodule
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
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Reference in New Issue