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https://github.com/antonblanchard/microwatt.git
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b56b46b7d1
This adds support for set associativity to the icache. It can still be direct mapped by setting NUM_WAYS to 1. The replacement policy uses a simple tree-PLRU for each set. This is only lightly tested, tests pass but I have to double check that we are using the ways effectively and not creating duplicates. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
47 lines
1.1 KiB
VHDL
47 lines
1.1 KiB
VHDL
library ieee;
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use ieee.std_logic_1164.all;
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use ieee.numeric_std.all;
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use ieee.math_real.all;
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entity cache_ram is
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generic(
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ROW_BITS : integer := 16;
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WIDTH : integer := 64
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);
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port(
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clk : in std_logic;
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rd_en : in std_logic;
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rd_addr : in std_logic_vector(ROW_BITS - 1 downto 0);
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rd_data : out std_logic_vector(WIDTH - 1 downto 0);
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wr_en : in std_logic;
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wr_addr : in std_logic_vector(ROW_BITS - 1 downto 0);
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wr_data : in std_logic_vector(WIDTH - 1 downto 0)
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);
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end cache_ram;
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architecture rtl of cache_ram is
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constant SIZE : integer := 2**ROW_BITS;
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type ram_type is array (0 to SIZE - 1) of std_logic_vector(WIDTH - 1 downto 0);
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signal ram : ram_type;
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attribute ram_style : string;
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attribute ram_style of ram : signal is "block";
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attribute ram_decomp : string;
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attribute ram_decomp of ram : signal is "power";
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begin
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process(clk)
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begin
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if rising_edge(clk) then
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if wr_en = '1' then
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ram(to_integer(unsigned(wr_addr))) <= wr_data;
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end if;
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if rd_en = '1' then
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rd_data <= ram(to_integer(unsigned(rd_addr)));
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end if;
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end if;
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end process;
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end;
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