microwatt/dcache_tb.vhdl

library ieee;
use ieee.std_logic_1164.all;

library work;
use work.common.all;
use work.wishbone_types.all;

entity dcache_tb is
end dcache_tb;

architecture behave of dcache_tb is
    signal clk          : std_ulogic;
    signal rst          : std_ulogic;

    signal d_in         : Loadstore1ToDcacheType;
    signal d_out        : DcacheToWritebackType;

    signal wb_bram_in   : wishbone_master_out;
    signal wb_bram_out  : wishbone_slave_out;

    constant clk_period : time := 10 ns;
begin
    dcache0: entity work.dcache
        generic map(
            LINE_SIZE => 64,
            NUM_LINES => 4
            )
        port map(
            clk => clk,
            rst => rst,
            d_in => d_in,
            d_out => d_out,
            wishbone_out => wb_bram_in,
            wishbone_in => wb_bram_out
            );

    -- BRAM Memory slave
    bram0: entity work.wishbone_bram_wrapper
        generic map(
            MEMORY_SIZE   => 1024,
            RAM_INIT_FILE => "icache_test.bin"
            )
        port map(
            clk => clk,
            rst => rst,
            wishbone_in => wb_bram_in,
            wishbone_out => wb_bram_out
            );

    clk_process: process
    begin
        clk <= '0';
        wait for clk_period/2;
        clk <= '1';
        wait for clk_period/2;
    end process;

    rst_process: process
    begin
        rst <= '1';
        wait for 2*clk_period;
        rst <= '0';
        wait;
    end process;

    stim: process
    begin
	-- Clear stuff
 	d_in.valid <= '0';
 	d_in.load <= '0';
 	d_in.nc <= '0';
 	d_in.addr <= (others => '0');
 	d_in.data <= (others => '0');
 	d_in.write_reg <= (others => '0');
 	d_in.length <= (others => '0');
 	d_in.byte_reverse <= '0';
 	d_in.sign_extend <= '0';
 	d_in.update <= '0';
 	d_in.update_reg <= (others => '0');

        wait for 4*clk_period;
	wait until rising_edge(clk);

	-- Cacheable read of address 4
	d_in.load <= '1';
	d_in.nc <= '0';
        d_in.addr <= x"0000000000000004";
        d_in.valid <= '1';
	wait until rising_edge(clk);
        d_in.valid <= '0';

	wait until rising_edge(clk) and d_out.write_enable = '1';
        assert d_out.valid = '1';
        assert d_out.write_data = x"0000000100000000"
	    report "data @" & to_hstring(d_in.addr) &
	    "=" & to_hstring(d_out.write_data) &
	    " expected 0000000100000000"
	    severity failure;
--      wait for clk_period;

	-- Cacheable read of address 30
	d_in.load <= '1';
	d_in.nc <= '0';
        d_in.addr <= x"0000000000000030";
        d_in.valid <= '1';
	wait until rising_edge(clk);
        d_in.valid <= '0';

	wait until rising_edge(clk) and d_out.write_enable = '1';
        assert d_out.valid = '1';
        assert d_out.write_data = x"0000000D0000000C"
	    report "data @" & to_hstring(d_in.addr) &
	    "=" & to_hstring(d_out.write_data) &
	    " expected 0000000D0000000C"
	    severity failure;

	-- Non-cacheable read of address 100
	d_in.load <= '1';
	d_in.nc <= '1';
        d_in.addr <= x"0000000000000100";
        d_in.valid <= '1';
	wait until rising_edge(clk);
	d_in.valid <= '0';
	wait until rising_edge(clk) and d_out.write_enable = '1';
        assert d_out.valid = '1';
        assert d_out.write_data = x"0000004100000040"
	    report "data @" & to_hstring(d_in.addr) &
	    "=" & to_hstring(d_out.write_data) &
	    " expected 0000004100000040"
	    severity failure;

	wait until rising_edge(clk);
	wait until rising_edge(clk);
	wait until rising_edge(clk);
	wait until rising_edge(clk);

        assert false report "end of test" severity failure;
        wait;

    end process;
end;