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- Removed dirty-bit which is not needed by Direct-Mapped Cache

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git-svn-id: http://moon:8086/svn/vhdl/trunk@113 cc03376c-175c-47c8-b038-4cd826a8556b
This commit is contained in:
jens
2008-10-25 17:08:37 +00:00
parent 8102a16c3c
commit 9918af8a12
1 changed files with 5 additions and 9 deletions
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lib/CPUs/MIPS/src/core/dcache.vhd
+5 -9
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@@ -92,14 +92,13 @@ END COMPONENT;
constant cache_index_width : natural := lg2(cache_size) - word_index_width; constant cache_index_width : natural := lg2(cache_size) - word_index_width;
constant tag_width : natural := 32 - word_index_width - cache_index_width - 2; constant tag_width : natural := 32 - word_index_width - cache_index_width - 2;
constant tag_parity_width : natural := 3; constant tag_parity_width : natural := 3;
constant tram_data_width : natural := 2 + tag_parity_width + tag_width; constant tram_data_width : natural := 1 + tag_parity_width + tag_width;
constant tram_addr_width : natural := cache_index_width; constant tram_addr_width : natural := cache_index_width;
subtype tram_data_t is unsigned (tram_data_width-1 downto 0); subtype tram_data_t is unsigned (tram_data_width-1 downto 0);
type dcache_entry_t is record type dcache_entry_t is record
valid : std_logic; valid : std_logic;
dirty : std_logic;
tv_p : unsigned(tag_parity_width-1 downto 0); tv_p : unsigned(tag_parity_width-1 downto 0);
tag : unsigned(tag_width-1 downto 0); tag : unsigned(tag_width-1 downto 0);
end record; end record;
@@ -112,9 +111,8 @@ END COMPONENT;
variable result : dcache_entry_t; variable result : dcache_entry_t;
begin begin
result.valid := x(0); result.valid := x(0);
result.dirty := x(1); result.tv_p := x(3 downto 1);
result.tv_p := x(4 downto 2); result.tag := x(tag_width+3 downto 4);
result.tag := x(tag_width+4 downto 5);
return result; return result;
end to_dcache_entry; end to_dcache_entry;
@@ -123,9 +121,8 @@ END COMPONENT;
variable result : tram_data_t; variable result : tram_data_t;
begin begin
result(0) := x.valid; result(0) := x.valid;
result(1) := x.dirty; result(3 downto 1) := x.tv_p;
result(4 downto 2) := x.tv_p; result(tag_width+3 downto 4) := x.tag;
result(tag_width+4 downto 5) := x.tag;
return result; return result;
end to_tram_data; end to_tram_data;
@@ -321,7 +318,6 @@ cache_state:
cache_entry_in.tv_p <= (others => '0'); cache_entry_in.tv_p <= (others => '0');
cache_entry_in.tag <= tag_index_reg; cache_entry_in.tag <= tag_index_reg;
cache_entry_in.valid <= '0'; cache_entry_in.valid <= '0';
cache_entry_in.dirty <= '0';
sn <= s; sn <= s;
case s is case s is