- dummy joypad read value added.

- fixed wrong dma start address

diff --git a/simulation/apu/apu.vhd b/simulation/apu/apu.vhd
index 9c5c804..adfe517 100644 (file)
--- a/simulation/apu/apu.vhd
+++ b/simulation/apu/apu.vhd
@@ -54,6 +54,8 @@ end  procedure;
 
 constant dsize     : integer := 8;
 constant OAM_DMA   : std_logic_vector(4 downto 0) := "10100";
+constant OAM_JP1   : std_logic_vector(4 downto 0) := "10110";
+constant OAM_JP2   : std_logic_vector(4 downto 0) := "10111";
 
 --oamaddr=0x2003
 constant OAMADDR   : std_logic_vector(15 downto 0) := "0010000000000011";
@@ -108,12 +110,26 @@ begin
     reg_set_p : process (rst_n, ce_n, r_nw, cpu_addr, cpu_d)
     begin
         if (rst_n = '1' and ce_n = '0') then
-            if(cpu_addr(4 downto 0) = OAM_DMA and r_nw = '0') then
-                dma_start_n <= '0';
-            else
-                dma_start_n <= '1';
+            if (r_nw = '0') then
+                --apu write
+                if (cpu_addr(4 downto 0) = OAM_DMA) then
+                    dma_start_n <= '0';
+                else
+                    dma_start_n <= '1';
+                end if;
+            elsif (r_nw = '1') then
+                --apu read
+                if (cpu_addr(4 downto 0) = OAM_JP1) then
+                    cpu_d <= (others => '0');
+                elsif (cpu_addr(4 downto 0) = OAM_JP2) then
+                    cpu_d <= (others => '0');
+                else
+                    --return dummy zero vale.
+                    cpu_d <= (others => '0');
+                end if;
             end if;
         else
+            cpu_d <= (others => 'Z');
             dma_start_n <= '1';
         end if; --if (rst_n = '1' and ce_n = '0') 
     end process;
@@ -155,6 +171,7 @@ begin
                 elsif (dma_status = DMA_ST_SETUP) then
                     cpu_addr <= OAMADDR;
                     cpu_d <= (others => '0');
+                    r_nw <= '0';
                     dma_next_status <= DMA_ST_PROCESS;
                 elsif (dma_status = DMA_ST_PROCESS) then
                     if (dma_addr(dsize - 1 downto 0) = "11111111" and dma_cnt_ce_n(0) = '1') then