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Merge pull request #413 from ozbenh/fix-io-bridge-qw-store

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soc: Fix issues with 64-bit stores to IO bridge
pull/415/head
Michael Neuling 2 years ago committed by GitHub
parent 413f2dc5d6 3f788e87dc
commit 432d9f3150
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GPG Key ID: 4AEE18F83AFDEB23
1 changed files with 33 additions and 22 deletions
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47
soc.vhdl
Unescape Escape View File

@ -476,6 +476,8 @@ begin
variable end_cyc : std_ulogic;
variable slave_io : slave_io_type;
variable match : std_ulogic_vector(31 downto 12);
variable dat_latch : std_ulogic_vector(31 downto 0);
variable sel_latch : std_ulogic_vector(3 downto 0);
begin
if rising_edge(system_clk) then
do_cyc := '0';
@ -488,6 +490,8 @@ begin
end_cyc := '1';
has_top := false;
has_bot := false;
dat_latch := (others => '0');
sel_latch := (others => '0');
else
case state is
when IDLE =>
@ -497,7 +501,11 @@ begin
-- Do we have a cycle ?
if wb_io_in.cyc = '1' and wb_io_in.stb = '1' then
-- Stall master until we are done, we are't (yet) pipelining
-- this, it's all slow IOs.
-- this, it's all slow IOs. Note: The current cycle has
-- already been accepted as "stall" was 0, this only blocks
-- the next one. This means that we must latch
-- everything we need from wb_io_in in *this* cycle.
--
wb_io_out.stall <= '1';

-- Start cycle downstream
@ -512,21 +520,22 @@ begin
has_top := wb_io_in.sel(7 downto 4) /= "0000";
has_bot := wb_io_in.sel(3 downto 0) /= "0000";

-- Remember the top word as it might be needed later
dat_latch := wb_io_in.dat(63 downto 32);
sel_latch := wb_io_in.sel(7 downto 4);

-- If we have a bottom word, handle it first, otherwise
-- send the top word down. XXX Split the actual mux out
-- and only generate a control signal.
-- send the top word down.
if has_bot then
if wb_io_in.we = '1' then
-- Always update out.dat, it doesn't matter if we
-- update it on reads and it saves mux
wb_sio_out.dat <= wb_io_in.dat(31 downto 0);
end if;
wb_sio_out.sel <= wb_io_in.sel(3 downto 0);

-- Wait for ack
state := WAIT_ACK_BOT;
else
if wb_io_in.we = '1' then
wb_sio_out.dat <= wb_io_in.dat(63 downto 32);
end if;
wb_sio_out.sel <= wb_io_in.sel(7 downto 4);

-- Bump address
@ -544,18 +553,14 @@ begin

-- Handle ack
if wb_sio_in.ack = '1' then
-- If it's a read, latch the data
if wb_sio_out.we = '0' then
-- Always latch the data, it doesn't matter if it was
-- a write and it saves a mux
wb_io_out.dat(31 downto 0) <= wb_sio_in.dat;
end if;

-- Do we have a "top" part as well ?
if has_top then
-- Latch data & sel
if wb_io_in.we = '1' then
wb_sio_out.dat <= wb_io_in.dat(63 downto 32);
end if;
wb_sio_out.sel <= wb_io_in.sel(7 downto 4);
wb_sio_out.dat <= dat_latch;
wb_sio_out.sel <= sel_latch;

-- Bump address and set STB
wb_sio_out.adr(0) <= '1';
@ -583,10 +588,9 @@ begin

-- Handle ack
if wb_sio_in.ack = '1' then
-- If it's a read, latch the data
if wb_sio_out.we = '0' then
-- Always latch the data, it doesn't matter if it was
-- a write and it saves a mux
wb_io_out.dat(63 downto 32) <= wb_sio_in.dat;
end if;

-- We are done, ack up, clear cyc downstram
end_cyc := '1';
@ -603,6 +607,13 @@ begin

-- Create individual registered cycle signals for the wishbones
-- going to the various peripherals
--
-- Note: This needs to happen on the cycle matching state = IDLE,
-- as wb_io_in content can only be relied upon on that one cycle.
-- This works here because do_cyc is a variable, not a signal, and
-- thus here we observe the value set above in the state machine
-- on the same cycle rather than the next one.
--
if do_cyc = '1' or end_cyc = '1' then
io_cycle_none <= '0';
io_cycle_syscon <= '0';

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