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Merge pull request #115 from antonblanchard/reduce-wishbone

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Reduce wishbone
pull/116/head
Anton Blanchard 6 years ago committed by GitHub
parent 247d7d4aa0 6dd0b514ac
commit 9620a76281
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GPG Key ID: 4AEE18F83AFDEB23
7 changed files with 47 additions and 35 deletions
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16
dcache.vhdl
Unescape Escape View File

@ -244,16 +244,16 @@ architecture rtl of dcache is
end;

-- Returns whether this is the last row of a line
function is_last_row(addr: std_ulogic_vector(63 downto 0)) return boolean is
function is_last_row(addr: wishbone_addr_type) return boolean is
constant ones : std_ulogic_vector(ROW_LINEBITS-1 downto 0) := (others => '1');
begin
return addr(LINE_OFF_BITS-1 downto ROW_OFF_BITS) = ones;
end;

-- Return the address of the next row in the current cache line
function next_row_addr(addr: std_ulogic_vector(63 downto 0)) return std_ulogic_vector is
function next_row_addr(addr: wishbone_addr_type) return std_ulogic_vector is
variable row_idx : std_ulogic_vector(ROW_LINEBITS-1 downto 0);
variable result : std_ulogic_vector(63 downto 0);
variable result : wishbone_addr_type;
begin
-- Is there no simpler way in VHDL to generate that 3 bits adder ?
row_idx := addr(LINE_OFF_BITS-1 downto ROW_OFF_BITS);
@ -573,6 +573,7 @@ begin
wr_data => wr_data
);
process(all)
variable tmp_adr : std_ulogic_vector(63 downto 0);
begin
-- Cache hit reads
do_read <= '1';
@ -595,7 +596,8 @@ begin
-- Otherwise, we might be doing a reload
wr_data <= wishbone_in.dat;
wr_sel <= (others => '1');
wr_addr <= std_ulogic_vector(to_unsigned(get_row(r1.wb.adr), ROW_BITS));
tmp_adr := (r1.wb.adr'left downto 0 => r1.wb.adr, others => '0');
wr_addr <= std_ulogic_vector(to_unsigned(get_row(tmp_adr), ROW_BITS));
end if;

-- The two actual write cases here
@ -733,7 +735,7 @@ begin
-- Prep for first wishbone read. We calculate the address of
-- the start of the cache line
--
r1.wb.adr <= d_in.addr(63 downto LINE_OFF_BITS) &
r1.wb.adr <= d_in.addr(r1.wb.adr'left downto LINE_OFF_BITS) &
(LINE_OFF_BITS-1 downto 0 => '0');
r1.wb.sel <= (others => '1');
r1.wb.we <= '0';
@ -743,7 +745,7 @@ begin

when OP_LOAD_NC =>
r1.wb.sel <= bus_sel;
r1.wb.adr <= d_in.addr(63 downto 3) & "000";
r1.wb.adr <= d_in.addr(r1.wb.adr'left downto 3) & "000";
r1.wb.cyc <= '1';
r1.wb.stb <= '1';
r1.wb.we <= '0';
@ -755,7 +757,7 @@ begin
r1.update_valid <= '1';
end if;
r1.wb.sel <= bus_sel;
r1.wb.adr <= d_in.addr(63 downto 3) & "000";
r1.wb.adr <= d_in.addr(r1.wb.adr'left downto 3) & "000";
r1.wb.dat <= store_data;
r1.wb.cyc <= '1';
r1.wb.stb <= '1';

13
icache.vhdl
Unescape Escape View File

@ -193,16 +193,17 @@ architecture rtl of icache is
end;

-- Returns whether this is the last row of a line
function is_last_row(addr: std_ulogic_vector(63 downto 0)) return boolean is
function is_last_row(addr: wishbone_addr_type) return boolean is
constant ones : std_ulogic_vector(ROW_LINEBITS-1 downto 0) := (others => '1');
begin
return addr(LINE_OFF_BITS-1 downto ROW_OFF_BITS) = ones;
end;

-- Return the address of the next row in the current cache line
function next_row_addr(addr: std_ulogic_vector(63 downto 0)) return std_ulogic_vector is
function next_row_addr(addr: wishbone_addr_type)
return std_ulogic_vector is
variable row_idx : std_ulogic_vector(ROW_LINEBITS-1 downto 0);
variable result : std_ulogic_vector(63 downto 0);
variable result : wishbone_addr_type;
begin
-- Is there no simpler way in VHDL to generate that 3 bits adder ?
row_idx := addr(LINE_OFF_BITS-1 downto ROW_OFF_BITS);
@ -297,6 +298,7 @@ begin
wr_data => wishbone_in.dat
);
process(all)
variable tmp_adr : std_ulogic_vector(63 downto 0);
begin
do_read <= '1';
do_write <= '0';
@ -305,7 +307,8 @@ begin
end if;
cache_out(i) <= dout;
rd_addr <= std_ulogic_vector(to_unsigned(req_row, ROW_BITS));
wr_addr <= std_ulogic_vector(to_unsigned(get_row(r.wb.adr), ROW_BITS));
tmp_adr := (r.wb.adr'left downto 0 => r.wb.adr, others => '0');
wr_addr <= std_ulogic_vector(to_unsigned(get_row(tmp_adr), ROW_BITS));
end process;
end generate;
@ -474,7 +477,7 @@ begin
-- Prep for first wishbone read. We calculate the address of
-- the start of the cache line
--
r.wb.adr <= i_in.nia(63 downto LINE_OFF_BITS) &
r.wb.adr <= i_in.nia(r.wb.adr'left downto LINE_OFF_BITS) &
(LINE_OFF_BITS-1 downto 0 => '0');
r.wb.cyc <= '1';
r.wb.stb <= '1';

6
simple_ram_behavioural.vhdl
Unescape Escape View File

@ -32,6 +32,7 @@ architecture behave of mw_soc_memory is
begin
wishbone_process: process(clk)
variable ret_dat: std_ulogic_vector(63 downto 0) := (others => '0');
variable adr: std_ulogic_vector(63 downto 0);
begin
wishbone_out.ack <= ret_ack and wishbone_in.cyc and wishbone_in.stb;
wishbone_out.dat <= ret_dat;
@ -49,15 +50,16 @@ begin
when IDLE =>
if wishbone_in.stb = '1' then
-- write
adr := (wishbone_in.adr'left downto 0 => wishbone_in.adr, others => '0');
if wishbone_in.we = '1' then
assert not(is_x(wishbone_in.dat)) and not(is_x(wishbone_in.adr)) severity failure;
report "RAM writing " & to_hstring(wishbone_in.dat) & " to " & to_hstring(wishbone_in.adr);
behavioural_write(wishbone_in.dat, wishbone_in.adr, to_integer(unsigned(wishbone_in.sel)), identifier);
behavioural_write(wishbone_in.dat, adr, to_integer(unsigned(wishbone_in.sel)), identifier);
reload <= reload + 1;
ret_ack <= '1';
state <= ACK;
else
behavioural_read(ret_dat, wishbone_in.adr, to_integer(unsigned(wishbone_in.sel)), identifier, reload);
behavioural_read(ret_dat, adr, to_integer(unsigned(wishbone_in.sel)), identifier, reload);
report "RAM reading from " & to_hstring(wishbone_in.adr) & " returns " & to_hstring(ret_dat);
ret_ack <= '1';
state <= ACK;

37
simple_ram_behavioural_tb.vhdl
Unescape Escape View File

@ -16,6 +16,11 @@ architecture behave of simple_ram_behavioural_tb is

signal w_in : wishbone_slave_out;
signal w_out : wishbone_master_out;

impure function to_adr(a: integer) return std_ulogic_vector is
begin
return std_ulogic_vector(to_unsigned(a, w_out.adr'length));
end;
begin
simple_ram_0: entity work.mw_soc_memory
generic map (
@ -56,7 +61,7 @@ begin
-- test various read lengths and alignments
w_out.stb <= '1';
w_out.sel <= "00000001";
w_out.adr <= x"0000000000000000";
w_out.adr <= to_adr(0);
assert w_in.ack = '0';
wait for clk_period;
assert w_in.ack = '1';
@ -67,7 +72,7 @@ begin

w_out.stb <= '1';
w_out.sel <= "00000001";
w_out.adr <= x"0000000000000001";
w_out.adr <= to_adr(1);
assert w_in.ack = '0';
wait for clk_period;
assert w_in.ack = '1';
@ -78,7 +83,7 @@ begin

w_out.stb <= '1';
w_out.sel <= "00000001";
w_out.adr <= x"0000000000000007";
w_out.adr <= to_adr(7);
assert w_in.ack = '0';
wait for clk_period;
assert w_in.ack = '1';
@ -89,7 +94,7 @@ begin

w_out.stb <= '1';
w_out.sel <= "00000011";
w_out.adr <= x"0000000000000000";
w_out.adr <= to_adr(0);
assert w_in.ack = '0';
wait for clk_period;
assert w_in.ack = '1';
@ -100,7 +105,7 @@ begin

w_out.stb <= '1';
w_out.sel <= "00000011";
w_out.adr <= x"0000000000000001";
w_out.adr <= to_adr(1);
assert w_in.ack = '0';
wait for clk_period;
assert w_in.ack = '1';
@ -111,7 +116,7 @@ begin

w_out.stb <= '1';
w_out.sel <= "00000011";
w_out.adr <= x"0000000000000007";
w_out.adr <= to_adr(7);
assert w_in.ack = '0';
wait for clk_period;
assert w_in.ack = '1';
@ -122,7 +127,7 @@ begin

w_out.stb <= '1';
w_out.sel <= "00001111";
w_out.adr <= x"0000000000000000";
w_out.adr <= to_adr(0);
assert w_in.ack = '0';
wait for clk_period;
assert w_in.ack = '1';
@ -133,7 +138,7 @@ begin

w_out.stb <= '1';
w_out.sel <= "00001111";
w_out.adr <= x"0000000000000001";
w_out.adr <= to_adr(1);
assert w_in.ack = '0';
wait for clk_period;
assert w_in.ack = '1';
@ -144,7 +149,7 @@ begin

w_out.stb <= '1';
w_out.sel <= "00001111";
w_out.adr <= x"0000000000000007";
w_out.adr <= to_adr(7);
assert w_in.ack = '0';
wait for clk_period;
assert w_in.ack = '1';
@ -155,7 +160,7 @@ begin

w_out.stb <= '1';
w_out.sel <= "11111111";
w_out.adr <= x"0000000000000000";
w_out.adr <= to_adr(0);
assert w_in.ack = '0';
wait for clk_period;
assert w_in.ack = '1';
@ -166,7 +171,7 @@ begin

w_out.stb <= '1';
w_out.sel <= "11111111";
w_out.adr <= x"0000000000000001";
w_out.adr <= to_adr(1);
assert w_in.ack = '0';
wait for clk_period;
assert w_in.ack = '1';
@ -177,7 +182,7 @@ begin

w_out.stb <= '1';
w_out.sel <= "11111111";
w_out.adr <= x"0000000000000007";
w_out.adr <= to_adr(7);
assert w_in.ack = '0';
wait for clk_period;
assert w_in.ack = '1';
@ -189,7 +194,7 @@ begin
-- test various write lengths and alignments
w_out.stb <= '1';
w_out.sel <= "00000001";
w_out.adr <= x"0000000000000000";
w_out.adr <= to_adr(0);
w_out.we <= '1';
w_out.dat(7 downto 0) <= x"0F";
assert w_in.ack = '0';
@ -201,7 +206,7 @@ begin

w_out.stb <= '1';
w_out.sel <= "00000001";
w_out.adr <= x"0000000000000000";
w_out.adr <= to_adr(0);
w_out.we <= '0';
assert w_in.ack = '0';
wait for clk_period;
@ -213,7 +218,7 @@ begin

w_out.stb <= '1';
w_out.sel <= "11111111";
w_out.adr <= x"0000000000000007";
w_out.adr <= to_adr(7);
w_out.we <= '1';
w_out.dat <= x"BADC0FFEBADC0FFE";
assert w_in.ack = '0';
@ -225,7 +230,7 @@ begin

w_out.stb <= '1';
w_out.sel <= "11111111";
w_out.adr <= x"0000000000000007";
w_out.adr <= to_adr(7);
w_out.we <= '0';
assert w_in.ack = '0';
wait for clk_period;

6
soc.vhdl
Unescape Escape View File

@ -111,11 +111,11 @@ begin
SLAVE_NONE);
variable slave : slave_type;
begin
-- Simple address decoder
-- Simple address decoder.
slave := SLAVE_NONE;
if wb_master_out.adr(63 downto 24) = x"0000000000" then
if wb_master_out.adr(31 downto 24) = x"00" then
slave := SLAVE_MEMORY;
elsif wb_master_out.adr(63 downto 24) = x"00000000c0" then
elsif wb_master_out.adr(31 downto 24) = x"c0" then
if wb_master_out.adr(23 downto 12) = x"002" then
slave := SLAVE_UART_0;
end if;

2
wishbone_debug_master.vhdl
Unescape Escape View File

@ -117,7 +117,7 @@ begin
dmi_ack <= dmi_req when (dmi_addr /= DBG_WB_DATA or state = DMI_WAIT) else '0';

-- Some WB signals are direct wires from registers or DMI
wb_out.adr <= reg_addr;
wb_out.adr <= reg_addr(wb_out.adr'left downto 0);
wb_out.dat <= dmi_din;
wb_out.sel <= reg_ctrl(7 downto 0);
wb_out.we <= dmi_wr;

2
wishbone_types.vhdl
Unescape Escape View File

@ -2,7 +2,7 @@ library ieee;
use ieee.std_logic_1164.all;

package wishbone_types is
constant wishbone_addr_bits : integer := 64;
constant wishbone_addr_bits : integer := 32;
constant wishbone_data_bits : integer := 64;
constant wishbone_sel_bits : integer := wishbone_data_bits/8;


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