Commit Graph

3 Commits (7577cb18fbd92ee3f5acad9084e4fe700092255a)

Author SHA1 Message Date
Benjamin Herrenschmidt 573b6b4bc4 soc: Rework interconnect
This changes the SoC interconnect such that the main 64-bit wishbone out
of the processor is first split between only 3 slaves (BRAM, DRAM and a
general "IO" bus) instead of all the slaves in the SoC.

The IO bus leg is then latched and down-converted to 32 bits data width,
before going through a second address decoder for the various IO devices.

This significantly reduces routing and timing pressure on the main bus,
allowing to get rid of frequent timing violations when synthetizing on
small'ish FPGAs such as the Artix-7 35T found on the original Arty board.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
5 years ago
Anton Blanchard f96d179f66 Some yosys fixes
This gets the yosys build further along, but I'm now chasing what looks
like a yosys bug.

Signed-off-by: Anton Blanchard <anton@linux.ibm.com>
5 years ago
Benjamin Herrenschmidt 3ac815823c fpga: Hookup Arty to litedram
The old toplevel.vhdl becomes top-generic.vhdl, which is to be used
by platforms that do not have a litedram option.

Arty has its own top-arty.vhdl which supports litedram and is now
hooked up

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
5 years ago