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- Cleaned up

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git-svn-id: http://moon:8086/svn/vhdl/trunk@354 cc03376c-175c-47c8-b038-4cd826a8556b
This commit is contained in:
jens
2009-02-15 17:32:48 +00:00
parent c3c42386d8
commit ea7e05ba30
2 changed files with 184 additions and 141 deletions
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lib/CPUs/MIPS/src/core/icache.vhd
+98 -68
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@@ -101,13 +101,14 @@ END COMPONENT;
return result;
end to_tag_ram_data;
type cache_state_t is (init, ready, flush, mem_request, mem_access, mem_wait, mem_data, upd_cache, rd_cache);
type cache_state_t is (init, ready, flush, mem_request, mem_access, mem_data, rd_cache);
signal s, sn : cache_state_t;
signal cache_busy : std_logic;
signal cache_miss : std_logic;
signal tag_match : 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);
@@ -127,16 +128,17 @@ END COMPONENT;
signal tag_ram_re : std_logic;
signal tag_ram_we : std_logic;
signal ram_index_count : natural range 0 to 2**word_index_width-1;
signal ram_index_count_rst : std_logic;
signal cache_index_count : natural range 0 to 2**cache_index_width-1;
signal cache_index_count_en : std_logic;
signal mem_index_count : natural range 0 to 2**word_index_width-1;
signal mem_index_count_en : std_logic;
signal mem_index_count_rst : std_logic;
signal cpu_reg_en : std_logic;
signal was_miss : std_logic;
signal data_write : 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_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 was_miss : std_logic;
begin
@@ -148,6 +150,10 @@ cpu_index_reg:
if RST_I = '1' then
cache_index_reg <= (others => '0');
tag_index_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
word_index_reg <= cpu_word_index;
cache_index_reg <= cpu_cache_index;
@@ -156,12 +162,28 @@ cpu_index_reg:
end if;
end process;
addr_windex_register:
process(CLK_I)
begin
if rising_edge(CLK_I) then
if request_count_en = '1'then
if SRDY_I = '1' then
addr_windex_reg <= addr_windex_reg + 1;
end if;
elsif cpu_reg_en = '1' then
addr_windex_reg <= cpu_word_index;
end if;
end if;
end process;
inst_tag_ram : dpram_1w1r
GENERIC MAP (
GENERIC MAP
(
addr_width => tag_ram_addr_width,
data_width => tag_ram_data_width
)
PORT MAP (
PORT MAP
(
clka => CLK_I,
clkb => CLK_I,
en_a => '1',
@@ -174,11 +196,13 @@ inst_tag_ram : dpram_1w1r
);
inst_data_ram : dpram_1w1r
GENERIC MAP (
GENERIC MAP
(
addr_width => lg2(cache_size),
data_width => word_t'length
)
PORT MAP (
PORT MAP
(
clka => CLK_I,
clkb => CLK_I,
en_a => '1',
@@ -209,31 +233,29 @@ cache_state_next:
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);
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 & to_unsigned(mem_index_count, word_index_width) & "00";
data_ram_addr_wr <= cache_index_reg & to_unsigned(ram_index_count, word_index_width);
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 <= data_write and ACK_I;
data_ram_we <= fill_count_en and ACK_I;
cache_state:
process(s, cache_miss, cache_index_count, ram_index_count, mem_index_count, cache_index_reg, ACK_I, tag_index_reg, cpu_en, SRDY_I, en)
process(s, cache_miss, flush_count_rdy, fill_count_rdy, request_count_rdy, tag_index_reg, cpu_en, SRDY_I, en)
begin
cpu_reg_en <= '0';
cache_busy <= '1';
tag_ram_we <= '0';
cache_index_count_en <= '0';
ram_index_count_rst <= '0';
mem_index_count_en <= '0';
mem_index_count_rst <= '0';
flush_count_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';
data_write <= '0';
tag_ram_addr_wr <= to_unsigned(cache_index_count, cache_index_width);
cache_entry_in.tv_p <= (others => '0');
cache_entry_in.tag <= tag_index_reg;
cache_entry_in.valid <= '0';
@@ -257,12 +279,12 @@ cache_state:
end if;
end if;
when flush =>
cache_index_count_en <= '1';
tag_ram_addr_wr <= to_unsigned(cache_index_count, cache_index_width);
flush_count_en <= '1';
tag_ram_we <= '1';
cache_entry_in.valid <= '0';
cache_entry_in.tag <= (others => '0');
if cache_index_count = 0 then
if flush_count_rdy = '1' then
tag_ram_we <= '0';
sn <= ready;
if cpu_en = '1' then
cpu_reg_en <= '1';
@@ -271,81 +293,89 @@ cache_state:
end if;
end if;
when mem_request =>
ram_index_count_rst <= '1';
mem_index_count_rst <= '1';
CYC_O <= '1';
if SRDY_I = '1' then
sn <= mem_access;
end if;
when mem_access =>
mem_index_count_en <= '1';
data_write <= '1';
CYC_O <= '1';
STB_O <= '1';
if mem_index_count = 2**word_index_width-1 then
if SRDY_I = '1' then
sn <= mem_data;
end if;
request_count_en <= '1';
fill_count_en <= '1';
CYC_O <= '1';
STB_O <= '1';
if request_count_rdy = '1' then
STB_O <= '0';
sn <= mem_data;
end if;
when mem_data =>
CYC_O <= '1';
data_write <= '1';
if ram_index_count = 2**word_index_width-1 then
if ACK_I = '1' then
sn <= upd_cache;
end if;
CYC_O <= '1';
fill_count_en <= '1';
if fill_count_rdy = '1' then
tag_ram_we <= '1';
cache_entry_in.valid <= '1';
sn <= rd_cache;
end if;
when upd_cache =>
tag_ram_addr_wr <= cache_index_reg;
tag_ram_we <= '1';
cache_entry_in.valid <= '1';
sn <= rd_cache;
when rd_cache =>
tag_ram_re <= '1';
data_ram_re <= '1';
was_miss <= '1';
sn <= ready;
when others =>
sn <= ready;
end case;
end process;
cache_index_counter:
flush_counter:
process(CLK_I)
begin
if rising_edge(CLK_I) then
if cache_index_count_en = '0' then
cache_index_count <= 2**cache_index_width-1;
elsif cache_index_count /= 0 then
cache_index_count <= cache_index_count - 1;
if flush_count_en = '0' then
flush_count_rdy <= '0';
flush_count <= 2**cache_index_width-1;
else
if flush_count /= 0 then
flush_count <= flush_count - 1;
else
flush_count_rdy <= '1';
end if;
end if;
end if;
end process;
ram_index_counter:
request_counter:
process(CLK_I)
begin
if rising_edge(CLK_I) then
if ram_index_count_rst = '1' then
ram_index_count <= 0;
elsif data_write = '1' and ACK_I = '1' then
if ram_index_count /= 2**word_index_width-1 then
ram_index_count <= ram_index_count + 1;
end if;
if request_count_en = '0' then
request_count_rdy <= '0';
request_count <= 2**word_index_width-1;
else
if SRDY_I = '1' then
if request_count /= 0 then
request_count <= request_count - 1;
else
request_count_rdy <= '1';
end if;
end if;
end if;
end if;
end process;
mem_index_counter:
fill_counter:
process(CLK_I)
begin
if rising_edge(CLK_I) then
if mem_index_count_rst = '1' then
mem_index_count <= 0;
elsif mem_index_count_en = '1' and SRDY_I = '1' then
if mem_index_count /= 2**word_index_width-1 then
mem_index_count <= mem_index_count + 1;
if fill_count_en = '0' then
fill_count_rdy <= '0';
fill_count <= 2**word_index_width-1;
else
if ACK_I = '1' then
if fill_count /= 0 then
fill_count <= fill_count - 1;
else
fill_count_rdy <= '1';
end if;
end if;
end if;
end if;