dcache: Add testbench

A very simple one for now...

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

Makefile

@@ -2,7 +2,7 @@ GHDL=ghdl
 GHDLFLAGS=--std=08 -Psim-unisim
 CFLAGS=-O2 -Wall
 
-all = core_tb simple_ram_behavioural_tb soc_reset_tb icache_tb multiply_tb dmi_dtm_tb divider_tb \
+all = core_tb simple_ram_behavioural_tb soc_reset_tb icache_tb dcache_tb multiply_tb dmi_dtm_tb divider_tb \
 	rotator_tb countzero_tb
 
 # XXX
@@ -38,6 +38,7 @@ plru_tb.o: plru.o
 icache.o: common.o wishbone_types.o plru.o cache_ram.o
 icache_tb.o: common.o wishbone_types.o icache.o simple_ram_behavioural.o
 dcache.o: common.o wishbone_types.o plru.o cache_ram.o
+dcache_tb.o: common.o wishbone_types.o dcache.o simple_ram_behavioural.o
 insn_helpers.o:
 loadstore1.o: common.o helpers.o
 logical.o: decode_types.o
@@ -81,6 +82,9 @@ fetch_tb: fetch_tb.o
 icache_tb: icache_tb.o
 	$(GHDL) -e $(GHDLFLAGS) -Wl,simple_ram_behavioural_helpers_c.o $@
 
+dcache_tb: dcache_tb.o
+	$(GHDL) -e $(GHDLFLAGS) -Wl,simple_ram_behavioural_helpers_c.o $@
+
 plru_tb: plru_tb.o
 	$(GHDL) -e $(GHDLFLAGS) $@
 

dcache_tb.vhdl

@@ -0,0 +1,139 @@
+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.mw_soc_memory
+        generic map(
+            MEMORY_SIZE   => 128,
+            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 for clk_period*4;
+
+        assert false report "end of test" severity failure;
+        wait;
+
+    end process;
+end;