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- redesigned

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- added invalidate_all and invalidate_at control
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git-svn-id: http://moon:8086/svn/vhdl/trunk@420 cc03376c-175c-47c8-b038-4cd826a8556b
This commit is contained in:
jens
2009-03-30 22:26:15 +00:00
parent 599380bd10
commit 2e1850c19b
2 changed files with 287 additions and 148 deletions
Download Patch File Download Diff File Expand all files Collapse all files
lib/CPUs/MIPS/src/core/icache.vhd
+138 -51
View File
@@ -51,6 +51,29 @@ COMPONENT dpram_1w1r
);
END COMPONENT;
COMPONENT dpram_2w2r is
GENERIC
(
addr_width : integer := 3;
data_width : integer := 8
);
PORT
(
clk_a : in STD_LOGIC;
clk_b : in STD_LOGIC;
en_a : in STD_LOGIC;
en_b : in STD_LOGIC;
we_a : in STD_LOGIC;
we_b : in STD_LOGIC;
addr_a : in unsigned (addr_width-1 downto 0);
addr_b : in unsigned (addr_width-1 downto 0);
din_a : in unsigned (data_width-1 downto 0);
din_b : in unsigned (data_width-1 downto 0);
dout_a : out unsigned (data_width-1 downto 0);
dout_b : out unsigned (data_width-1 downto 0)
);
END COMPONENT;
constant word_index_width : natural := lg2(line_size);
constant cache_index_width : natural := lg2(cache_size) - word_index_width;
constant tag_width : natural := 32 - word_index_width - cache_index_width - 2;
@@ -69,7 +92,7 @@ END COMPONENT;
alias cpu_word_index is cpu_addr(word_index_width+1 downto 2);
alias cpu_cache_index is cpu_addr(cache_index_width+word_index_width+1 downto word_index_width+2);
alias cpu_tag is cpu_addr(tag_width+cache_index_width+word_index_width+1 downto cache_index_width+word_index_width+2);
function to_icache_entry(x : tag_ram_data_t) return icache_entry_t is
variable result : icache_entry_t;
begin
@@ -90,47 +113,63 @@ END COMPONENT;
return result;
end to_tag_ram_data;
type cache_state_t is (init, ready, flush, mem_request, mem_access, mem_data, rd_cache);
type cache_state_t is (init, ready, invalidate, flush, mem_request, mem_access, mem_data, rd_cache, upd_cache);
signal s, sn : cache_state_t;
signal cache_req : std_logic;
signal cache_ack : std_logic;
signal cache_busy : std_logic;
signal cache_miss : std_logic;
signal tag_match : std_logic;
signal cache_miss_inv : std_logic;
signal tag_match_inv : std_logic;
signal word_index_reg : unsigned(word_index_width-1 downto 0);
signal addr_windex_reg : unsigned(word_index_width-1 downto 0);
signal cache_index_reg : unsigned(cache_index_width-1 downto 0);
signal tag_index_reg : unsigned(tag_width-1 downto 0);
signal cache_index_inv : unsigned(cache_index_width-1 downto 0);
signal tag_reg : unsigned(tag_width-1 downto 0);
signal tag_inv : unsigned(tag_width-1 downto 0);
signal tag_reg_inv : unsigned(tag_width-1 downto 0);
signal cache_entry_in : icache_entry_t;
signal cache_entry_out : icache_entry_t;
signal cache_entry_out_inv : icache_entry_t;
signal data_ram_addr_rd : unsigned(lg2(cache_size)-1 downto 0);
signal data_ram_data_rd : word_t;
signal data_ram_addr_wr : unsigned(lg2(cache_size)-1 downto 0);
signal data_ram_data_wr : word_t;
signal data_ram_we : std_logic;
signal data_ram_re : std_logic;
signal tag_ram_addr_rd : unsigned(cache_index_width-1 downto 0);
signal tag_ram_data_rd : tag_ram_data_t;
signal tag_ram_data_rd_inv : tag_ram_data_t;
signal tag_ram_addr_wr : unsigned(cache_index_width-1 downto 0);
signal tag_ram_data_wr : tag_ram_data_t;
signal tag_ram_re : std_logic;
signal tag_ram_we : std_logic;
signal fill_count : natural range 0 to 2**word_index_width-1;
signal fill_count_en : std_logic;
signal fill_count_rdy : std_logic;
signal flush_count : natural range 0 to 2**cache_index_width-1;
signal flush_count_rst : std_logic;
signal flush_count_en : std_logic;
signal flush_count_rdy : std_logic;
signal request_count : natural range 0 to 2**word_index_width-1;
signal request_count_en : std_logic;
signal request_count_rdy : std_logic;
signal cpu_reg_en : std_logic;
signal ram_read_en : std_logic;
signal was_miss : std_logic;
signal invalidate_all : std_logic;
signal invalidate_ack : std_logic;
signal invalidate_en : std_logic;
signal invalidate_req : std_logic;
begin
ram_read_en <= cpu_en or was_miss;
cache_index_inv <= ctrl.inv_addr(cache_index_width+word_index_width+1 downto word_index_width+2);
tag_inv <= ctrl.inv_addr(tag_width+cache_index_width+word_index_width+1 downto cache_index_width+word_index_width+2);
cpu_index_reg:
process(CLK_I)
@@ -138,15 +177,15 @@ cpu_index_reg:
if rising_edge(CLK_I) then
if RST_I = '1' then
cache_index_reg <= (others => '0');
tag_index_reg <= (others => '0');
tag_reg <= (others => '0');
elsif fill_count_en = '1' then
if ACK_I = '1' then
word_index_reg <= word_index_reg + 1;
end if;
elsif cpu_reg_en = '1' then
elsif cache_busy = '0' then
word_index_reg <= cpu_word_index;
cache_index_reg <= cpu_cache_index;
tag_index_reg <= cpu_tag;
tag_reg <= cpu_tag;
end if;
end if;
end process;
@@ -159,13 +198,44 @@ addr_windex_register:
if SRDY_I = '1' then
addr_windex_reg <= addr_windex_reg + 1;
end if;
elsif cpu_reg_en = '1' then
elsif cache_busy = '0' then
addr_windex_reg <= cpu_word_index;
end if;
end if;
end process;
inst_tag_ram : dpram_1w1r
cpu_request_register:
process(CLK_I)
begin
if rising_edge(CLK_I) then
if RST_I = '1' then
cache_req <= '0';
elsif cpu_en = '1' then
if cache_busy = '0' then
cache_req <= en;
end if;
elsif cache_ack = '1' then
cache_req <= '0';
end if;
end if;
end process;
cache_invalidate_request:
process(CLK_I)
begin
if rising_edge(CLK_I) then
if RST_I = '1' or ctrl.inv_all = '1' or ctrl.inv_at = '1' then
invalidate_req <= '1';
invalidate_all <= ctrl.inv_all or RST_I;
tag_reg_inv <= tag_inv;
elsif invalidate_ack = '1' then
invalidate_req <= '0';
invalidate_all <= '0';
end if;
end if;
end process;
inst_tag_ram : dpram_2w2r
GENERIC MAP
(
addr_width => tag_ram_addr_width,
@@ -173,14 +243,17 @@ inst_tag_ram : dpram_1w1r
)
PORT MAP
(
clka => CLK_I,
clkb => CLK_I,
clk_a => CLK_I,
clk_b => CLK_I,
en_a => '1',
en_b => tag_ram_re,
en_b => ram_read_en,
we_a => tag_ram_we,
we_b => '0',
addr_a => tag_ram_addr_wr,
addr_b => tag_ram_addr_rd,
din_a => tag_ram_data_wr,
din_b => tag_ram_data_wr,
dout_a => tag_ram_data_rd_inv,
dout_b => tag_ram_data_rd
);
@@ -195,7 +268,7 @@ inst_data_ram : dpram_1w1r
clka => CLK_I,
clkb => CLK_I,
en_a => '1',
en_b => data_ram_re,
en_b => ram_read_en,
we_a => data_ram_we,
addr_a => data_ram_addr_wr,
addr_b => data_ram_addr_rd,
@@ -203,7 +276,6 @@ inst_data_ram : dpram_1w1r
dout_b => data_ram_data_rd
);
cache_state_next:
process(CLK_I)
begin
@@ -216,70 +288,86 @@ cache_state_next:
end if;
end process;
ADDR_O <= tag_reg & cache_index_reg & addr_windex_reg & "00";
cpu_busy <= cache_busy;
cpu_dout <= data_ram_data_rd;
tag_match <= '1' when tag_index_reg = cache_entry_out.tag else '0';
cache_miss <= not (tag_match and cache_entry_out.valid);
tag_ram_data_wr <= to_tag_ram_data(cache_entry_in);
tag_ram_addr_wr <= to_unsigned(flush_count, cache_index_width) when flush_count_en = '1' else cache_index_reg;
tag_ram_addr_rd <= cpu_cache_index when was_miss = '0' else cache_index_reg;
cache_entry_out <= to_icache_entry(tag_ram_data_rd);
tag_match <= '1' when tag_reg = cache_entry_out.tag else '0';
cache_miss <= not (tag_match and cache_entry_out.valid);
cache_entry_out_inv <= to_icache_entry(tag_ram_data_rd_inv);
tag_match_inv <= '1' when tag_reg_inv = cache_entry_out_inv.tag else '0';
cache_miss_inv <= not (tag_match_inv and cache_entry_out_inv.valid);
tag_ram_data_wr <= to_tag_ram_data(cache_entry_in);
tag_ram_addr_wr <= to_unsigned(flush_count, cache_index_width) when invalidate_en = '1' else cache_index_reg;
tag_ram_addr_rd <= cpu_cache_index when was_miss = '0' else cache_index_reg;
data_ram_addr_rd <= (cpu_cache_index & cpu_word_index) when was_miss = '0' else (cache_index_reg & word_index_reg);
ADDR_O <= tag_index_reg & cache_index_reg & addr_windex_reg & "00";
data_ram_addr_wr <= cache_index_reg & word_index_reg;
data_ram_data_wr <= DAT_I;
data_ram_we <= fill_count_en and ACK_I;
cache_state:
process(s, cache_miss, flush_count_rdy, fill_count_rdy, request_count_rdy, tag_index_reg, cpu_en, SRDY_I, en)
process(s, cache_req, cache_miss, cache_miss_inv, flush_count_rdy, fill_count_rdy, request_count_rdy, tag_reg, SRDY_I, invalidate_req, invalidate_all)
begin
cpu_reg_en <= '0';
cache_busy <= '1';
cache_busy <= cache_req;
cache_ack <= '0';
tag_ram_we <= '0';
flush_count_en <= '0';
flush_count_rst <= '0';
invalidate_en <= '0';
request_count_en <= '0';
fill_count_en <= '0';
CYC_O <= '0';
STB_O <= '0';
data_ram_re <= '0';
tag_ram_re <= '0';
was_miss <= '0';
invalidate_ack <= '0';
cache_entry_in.tv_p <= (others => '0');
cache_entry_in.tag <= tag_index_reg;
cache_entry_in.tag <= tag_reg;
cache_entry_in.valid <= '0';
sn <= s;
case s is
when init =>
sn <= flush;
sn <= ready;
when ready =>
if en = '1' then
cache_busy <= '0';
if invalidate_req = '1' then
sn <= invalidate;
invalidate_en <= '1';
elsif cache_req = '1' then
if cache_miss = '1' then
sn <= mem_request;
cpu_reg_en <= '0';
cache_busy <= '1';
CYC_O <= '1';
elsif cpu_en = '1' then
cpu_reg_en <= '1';
data_ram_re <= '1';
tag_ram_re <= '1';
else
cache_busy <= '0';
cache_ack <= '1';
end if;
end if;
when invalidate =>
sn <= rd_cache;
invalidate_en <= '1';
invalidate_ack <= '1';
if invalidate_all = '1' then
sn <= flush;
flush_count_rst <= '1';
elsif cache_miss_inv = '0' then
tag_ram_we <= '1';
cache_entry_in.valid <= '0';
cache_entry_in.tag <= (others => '0');
sn <= rd_cache;
end if;
when flush =>
flush_count_en <= '1';
invalidate_en <= '1';
tag_ram_we <= '1';
cache_entry_in.valid <= '0';
cache_entry_in.tag <= (others => '0');
if flush_count_rdy = '1' then
tag_ram_we <= '0';
sn <= ready;
if cpu_en = '1' then
cpu_reg_en <= '1';
data_ram_re <= '1';
tag_ram_re <= '1';
end if;
sn <= rd_cache;
end if;
when mem_request =>
CYC_O <= '1';
@@ -304,11 +392,8 @@ cache_state:
sn <= rd_cache;
end if;
when rd_cache =>
tag_ram_re <= '1';
data_ram_re <= '1';
was_miss <= '1';
sn <= ready;
was_miss <= '1';
sn <= ready;
when others =>
sn <= ready;
end case;
@@ -319,10 +404,12 @@ flush_counter:
process(CLK_I)
begin
if rising_edge(CLK_I) then
if flush_count_en = '0' then
if ctrl.inv_at = '1' then
flush_count <= to_integer(cache_index_inv);
elsif flush_count_rst = '1' then
flush_count_rdy <= '0';
flush_count <= 2**cache_index_width-1;
else
elsif flush_count_en = '1' then
if flush_count /= 0 then
flush_count <= flush_count - 1;
else