This makes the 64-bit wishbone buses have the address expressed in
units of doublewords (64 bits), and similarly for the 32-bit buses the
address is in units of words (32 bits). This is to comply with the
wishbone spec. Previously the addresses on the wishbone buses were in
units of bytes regardless of the bus data width, which is not correct
and caused problems with interfacing with externally-generated logic.
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
This adds litesdcard.v generated from the litex/litesdcard project,
along with logic in top-arty.vhdl to connect it into the system.
There is now a DMA wishbone coming in to soc.vhdl which is narrower
than the other wishbone masters (it has 32-bit data rather than
64-bit) so there is a widening/narrowing adapter between it and the
main wishbone master arbiter.
Also, litesdcard generates a non-pipelined wishbone for its DMA
connection, which needs to be converted to a pipelined wishbone. We
have a latch on both the incoming and outgoing sides of the wishbone
in order to help make timing (at the cost of two extra cycles of
latency).
litesdcard generates an interrupt signal which is wired up to input 3
of the ICS (IRQ 19).
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
This makes it easier to parse the records in verilog because they
are getting flattened into an array of bits by ghdl/yosys.
Signed-off-by: Anton Blanchard <anton@linux.ibm.com>
Currently, when not using litedram, the top level still has to hook
up "dummy" wishbones to the main dram and control dram busses coming
out of the SoC and provide ack signals.
Instead, make the SoC generate the acks internally when not using
litedram and use defaults to make the wiring entirely optional.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
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>
- Changing use of others in core files to satisfy VCS
- Adding workaround for VCS subtype constraint inconsistencies in common.vhdl
Signed-off-by: Jonathan Balkind <jbalkind@princeton.edu>
For now ... it reduces the routing pressure on the FPGA
This needs manual adjustment of the address decoder in soc.vhdl, at
least until I can figure out how to deal with std_match
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
# Conflicts:
# soc.vhdl
# Conflicts:
# soc.vhdl
This replaces loadstore2 with a dcache
The dcache unit is losely based on the icache one (same basic cache
layout), but has some significant logic additions to deal with stores,
loads with update, non-cachable accesses and other differences due to
operating in the execution part of the pipeline rather than the fetch
part.
The cache is store-through, though a hit with an existing line will
update the line rather than invalidate it.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Paul Mackerras
Anton Blanchard