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microwatt/fpga/top-caravel.vhdl

196 lines
6.1 KiB
VHDL

library ieee;
use ieee.std_logic_1164.all;
use ieee.numeric_std.all;
library work;
use work.wishbone_types.all;
entity toplevel is
generic (
MEMORY_SIZE : integer := 8192;
RAM_INIT_FILE : string := "firmware.hex";
RESET_LOW : boolean := true;
CLK_INPUT : positive := 100000000;
CLK_FREQUENCY : positive := 100000000;
HAS_FPU : boolean := false;
NO_BRAM : boolean := false;
DISABLE_FLATTEN_CORE : boolean := false;
SPI_FLASH_OFFSET : integer := 0;
SPI_FLASH_DEF_CKDV : natural := 4;
SPI_FLASH_DEF_QUAD : boolean := false;
LOG_LENGTH : natural := 0;
UART_IS_16550 : boolean := true;
HAS_UART1 : boolean := false;
HAS_JTAG : boolean := true
);
port(
ext_clk : in std_ulogic;
ext_rst : in std_ulogic;
-- UART0 signals:
uart0_txd : out std_ulogic;
uart0_rxd : in std_ulogic;
-- UART1 signals:
uart1_txd : out std_ulogic;
uart1_rxd : in std_ulogic;
-- SPI
spi_flash_cs_n : out std_ulogic;
spi_flash_clk : out std_ulogic;
spi_flash_sdat_i : in std_ulogic_vector(3 downto 0);
spi_flash_sdat_o : out std_ulogic_vector(3 downto 0);
spi_flash_sdat_oe : out std_ulogic_vector(3 downto 0);
-- JTAG signals:
jtag_tck : in std_ulogic;
jtag_tdi : in std_ulogic;
jtag_tms : in std_ulogic;
jtag_trst : in std_ulogic;
jtag_tdo : out std_ulogic;
-- Bill's bus
oib_clk : out std_ulogic;
ob_data : out std_ulogic_vector(7 downto 0);
ob_pty : out std_ulogic;
ib_data : in std_ulogic_vector(7 downto 0);
ib_pty : in std_ulogic;
-- Add an I/O pin to select fetching from flash on reset
alt_reset : in std_ulogic;
-- unused
wb_ext_io_out : out wb_io_slave_out
);
end entity toplevel;
architecture behaviour of toplevel is
-- reset signals
signal system_rst : std_ulogic;
-- external bus wishbone connection
signal wb_dram_out : wishbone_master_out;
signal wb_dram_in : wishbone_slave_out;
-- external bus
signal wb_mc_adr : wishbone_addr_type;
signal wb_mc_dat_o : wishbone_data_type;
signal wb_mc_cyc : std_ulogic;
signal wb_mc_stb : std_ulogic;
signal wb_mc_sel : wishbone_sel_type;
signal wb_mc_we : std_ulogic;
signal wb_mc_dat_i : wishbone_data_type;
signal wb_mc_ack : std_ulogic;
signal wb_mc_stall : std_ulogic;
begin
system_rst <= not ext_rst when RESET_LOW else ext_rst;
-- Unused, but tie it off
wb_ext_io_out <= wb_io_slave_out_init;
-- Main SoC
soc0: entity work.soc
generic map(
MEMORY_SIZE => MEMORY_SIZE,
RAM_INIT_FILE => RAM_INIT_FILE,
SIM => false,
CLK_FREQ => CLK_FREQUENCY,
HAS_FPU => HAS_FPU,
HAS_DRAM => true,
DRAM_SIZE => 0,
DRAM_INIT_SIZE => 0,
DISABLE_FLATTEN_CORE => DISABLE_FLATTEN_CORE,
HAS_SPI_FLASH => true,
SPI_FLASH_DLINES => 4,
SPI_FLASH_OFFSET => SPI_FLASH_OFFSET,
SPI_FLASH_DEF_CKDV => SPI_FLASH_DEF_CKDV,
SPI_FLASH_DEF_QUAD => SPI_FLASH_DEF_QUAD,
LOG_LENGTH => LOG_LENGTH,
UART0_IS_16550 => UART_IS_16550,
HAS_UART1 => HAS_UART1,
HAS_JTAG => HAS_JTAG
)
port map (
-- System signals
system_clk => ext_clk,
rst => system_rst,
-- UART signals
uart0_txd => uart0_txd,
uart0_rxd => uart0_rxd,
-- UART1 signals
uart1_txd => uart1_txd,
uart1_rxd => uart1_rxd,
-- SPI signals
spi_flash_sck => spi_flash_clk,
spi_flash_cs_n => spi_flash_cs_n,
spi_flash_sdat_o => spi_flash_sdat_o,
spi_flash_sdat_oe => spi_flash_sdat_oe,
spi_flash_sdat_i => spi_flash_sdat_i,
-- JTAG signals
jtag_tck => jtag_tck,
jtag_tdi => jtag_tdi,
jtag_tms => jtag_tms,
jtag_trst => jtag_trst,
jtag_tdo => jtag_tdo,
-- Use DRAM wishbone for Bill's bus
wb_dram_in => wb_dram_out,
wb_dram_out => wb_dram_in,
-- Reset PC to flash offset 0 (ie 0xf000000)
alt_reset => alt_reset
);
mc0: entity work.mc
generic map(
WB_AW => 32, -- wishbone_addr_bits
WB_DW => 64, -- wishbone_data_bits
OIB_DW => 8,
OIB_RATIO => 2, -- bill said this
BAR_INIT => x"1fff" -- dram has 512 bit space. CPU gives
-- top 3 bits as 0. carve off small
-- chunk at top for config space.
)
port map (
clk => ext_clk,
rst => system_rst,
wb_cyc => wb_mc_cyc,
wb_stb => wb_mc_stb,
wb_we => wb_mc_we,
wb_addr => wb_mc_adr,
wb_wr_data => wb_mc_dat_o,
wb_sel => wb_mc_sel,
wb_ack => wb_mc_ack,
-- wb_err => wb_mc_err, ??
wb_stall => wb_mc_stall,
wb_rd_data => wb_mc_dat_i,
oib_clk => oib_clk,
ob_data => ob_data,
ob_pty => ob_pty,
ib_data => ib_data,
ib_pty => ib_pty
-- err => ob _err,
-- int => ob int
);
-- External bus wishbone
wb_mc_adr <= wb_dram_out.adr;
wb_mc_dat_o <= wb_dram_out.dat;
wb_mc_cyc <= wb_dram_out.cyc;
wb_mc_stb <= wb_dram_out.stb;
wb_mc_sel <= wb_dram_out.sel;
wb_mc_we <= wb_dram_out.we;
wb_dram_in.dat <= wb_mc_dat_i;
wb_dram_in.ack <= wb_mc_ack;
wb_dram_in.stall <= wb_mc_stall;
end architecture behaviour;