scroll reg working..

diff --git a/simulation/ppu/render.vhd b/simulation/ppu/render.vhd
index 582af66..31a3f43 100644 (file)
--- a/simulation/ppu/render.vhd
+++ b/simulation/ppu/render.vhd
@@ -248,6 +248,7 @@ signal clk_n            : std_logic;
 
 --timing adjust
 signal io_cnt           : std_logic_vector(0 downto 0);
+signal vram_io          : std_logic;
 
 --vram i/o
 signal io_oe_n          : std_logic;
@@ -262,6 +263,8 @@ signal cur_x            : std_logic_vector(X_SIZE - 1 downto 0);
 signal cur_y            : std_logic_vector(X_SIZE - 1 downto 0);
 signal next_x           : std_logic_vector(X_SIZE - 1 downto 0);
 signal next_y           : std_logic_vector(X_SIZE - 1 downto 0);
+signal scrl_x           : std_logic_vector(X_SIZE - 1 downto 0);
+signal scrl_y           : std_logic_vector(X_SIZE - 1 downto 0);
 
 signal nt_we_n          : std_logic;
 signal disp_nt          : std_logic_vector (dsize - 1 downto 0);
@@ -356,17 +359,19 @@ begin
 
     cnt_x_en_n <= '0';
 
-    ale <= io_cnt(0) when ppu_mask(PPUSBG) = '1' and
+    vram_io <= io_cnt(0) when ppu_scroll_x(0) = '0' else
+               not io_cnt(0);
+    ale <= vram_io when ppu_mask(PPUSBG) = '1' and
                 (cur_y < conv_std_logic_vector(VSCAN, X_SIZE) or 
                 cur_y = conv_std_logic_vector(VSCAN_MAX - 1, X_SIZE)) else
-           io_cnt(0) when ppu_mask(PPUSSP) = '1' and
+           vram_io when ppu_mask(PPUSSP) = '1' and
                 (cur_y < conv_std_logic_vector(VSCAN, X_SIZE) or 
                 cur_y = conv_std_logic_vector(VSCAN_MAX - 1, X_SIZE)) else
            'Z';
-    rd_n <= io_cnt(0) when ppu_mask(PPUSBG) = '1' and
+    rd_n <= vram_io when ppu_mask(PPUSBG) = '1' and
                 (cur_y < conv_std_logic_vector(VSCAN, X_SIZE) or 
                 cur_y = conv_std_logic_vector(VSCAN_MAX - 1, X_SIZE)) else
-            io_cnt(0) when ppu_mask(PPUSSP) = '1' and
+            vram_io when ppu_mask(PPUSSP) = '1' and
                 (cur_y < conv_std_logic_vector(VSCAN, X_SIZE) or 
                 cur_y = conv_std_logic_vector(VSCAN_MAX - 1, X_SIZE)) else
             'Z';
@@ -377,10 +382,10 @@ begin
                 (cur_y < conv_std_logic_vector(VSCAN, X_SIZE) or 
                 cur_y = conv_std_logic_vector(VSCAN_MAX - 1, X_SIZE)) else
             'Z';
-    io_oe_n <= not io_cnt(0) when ppu_mask(PPUSBG) = '1' and
+    io_oe_n <= not vram_io when ppu_mask(PPUSBG) = '1' and
                 (cur_y < conv_std_logic_vector(VSCAN, X_SIZE) or 
                 cur_y = conv_std_logic_vector(VSCAN_MAX - 1, X_SIZE)) else
-               not io_cnt(0) when ppu_mask(PPUSSP) = '1' and
+               not vram_io when ppu_mask(PPUSSP) = '1' and
                 (cur_y < conv_std_logic_vector(VSCAN, X_SIZE) or 
                 cur_y = conv_std_logic_vector(VSCAN_MAX - 1, X_SIZE)) else
                '1';
@@ -396,10 +401,19 @@ begin
     io_cnt_inst : counter_register generic map (1, 1)
             port map (clk, cnt_x_res_n, '0', '1', (others => '0'), io_cnt);
 
+    --take scroll position into account
+    scrl_x <= cur_x + ppu_scroll_x
+                    when cur_x + ppu_scroll_x <= "101010100" else
+              cur_x + ppu_scroll_x + "110101101";
+
+    scrl_y <= cur_y + ppu_scroll_y
+                    when cur_y + ppu_scroll_y <= "100000101" else
+              cur_y + ppu_scroll_y + "111111100";
+
     ---x pos is 8 cycle ahead of current pos.
-    next_x <= cur_x + "000010000" 
-                    when cur_x <  conv_std_logic_vector(HSCAN_NEXT_START, X_SIZE) else
-              cur_x + "011000000";
+    next_x <= scrl_x + "000010000" 
+                    when scrl_x <  conv_std_logic_vector(HSCAN_NEXT_START, X_SIZE) else
+              scrl_x + "011000000";
     next_y <= cur_y 
                     when cur_x <=  conv_std_logic_vector(HSCAN, X_SIZE) else
               "000000000" 
@@ -429,8 +443,8 @@ begin
                  vram_ad(4) & vram_ad(5) & vram_ad(6) & vram_ad(7)) & 
                 disp_ptn_h (dsize downto 1);
 
-    ptn_en_n <= '1' when cur_x = conv_std_logic_vector(0, X_SIZE) else
-                '0' when cur_x <= conv_std_logic_vector(HSCAN_NEXT_EXTRA, X_SIZE) else
+    ptn_en_n <= '1' when scrl_x = conv_std_logic_vector(0, X_SIZE) else
+                '0' when scrl_x <= conv_std_logic_vector(HSCAN_NEXT_EXTRA, X_SIZE) else
                 '1';
 
     ptn_l_inst : d_flip_flop generic map(dsize)
@@ -721,7 +735,7 @@ end;
                     d_print("cur_y: " & conv_hex16(conv_integer(cur_y)));
 
                     ----fetch next tile byte.
-                    if (cur_x (2 downto 0) = "001" ) then
+                    if (scrl_x (2 downto 0) = "001" ) then
                         --vram addr is incremented every 8 cycle.
                         --name table at 0x2000
                         vram_addr(9 downto 0) 
@@ -729,35 +743,35 @@ end;
                                 & next_x(dsize - 1 downto 3);
                         vram_addr(asize - 1 downto 10) <= "10" & ppu_ctrl(PPUBNA downto 0);
                     end if;
-                    if (cur_x (2 downto 0) = "010" ) then
+                    if (scrl_x (2 downto 0) = "010" ) then
                         nt_we_n <= '0';
                     else
                         nt_we_n <= '1';
                     end if;
 
                     ----fetch attr table byte.
-                    if (cur_x (4 downto 0) = "11011" or 
-                            cur_x = conv_std_logic_vector(HSCAN_NEXT_START + 3, X_SIZE)) then
+                    if (scrl_x (4 downto 0) = "11011" or 
+                            scrl_x = conv_std_logic_vector(HSCAN_NEXT_START + 3, X_SIZE)) then
                         --attribute table is loaded every 32 cycle.
                         --attr table at 0x23c0
                         vram_addr(dsize - 1 downto 0) <= "11000000" +
                                 ("00" & next_y(7 downto 5) & next_x(7 downto 5));
                         vram_addr(asize - 1 downto dsize) <= "10" &
                                 ppu_ctrl(PPUBNA downto 0) & "11";
-                    end if;--if (cur_x (2 downto 0) = "010" ) then
-                    if (cur_x (4 downto 0) = "11100" or 
-                            cur_x = conv_std_logic_vector(HSCAN_NEXT_START + 4, X_SIZE)) then
+                    end if;--if (scrl_x (2 downto 0) = "010" ) then
+                    if (scrl_x (4 downto 0) = "11100" or 
+                            scrl_x = conv_std_logic_vector(HSCAN_NEXT_START + 4, X_SIZE)) then
                         attr_we_n <= '0';
                     else
                         attr_we_n <= '1';
                     end if;
-                    if (cur_x (4 downto 0) = "00000" ) then
+                    if (scrl_x (4 downto 0) = "00000" ) then
                         disp_attr_we_n <= '0';
                     else
                         disp_attr_we_n <= '1';
                     end if;
                     ---attribute is shifted every 16 bit.
-                    if (cur_x (3 downto 0) = "0000" ) then
+                    if (scrl_x (3 downto 0) = "0000" ) then
                         attr_ce_n <= '0';
                     else
                         attr_ce_n <= '1';
@@ -768,30 +782,30 @@ end;
                         cur_x > conv_std_logic_vector(HSCAN_NEXT_START, X_SIZE)) then
 
                         ----fetch pattern table low byte.
-                        if (cur_x (2 downto 0) = "101" ) then
+                        if (scrl_x (2 downto 0) = "101" ) then
                             --vram addr is incremented every 8 cycle.
                             vram_addr <= "0" & ppu_ctrl(PPUBPA) & 
                                             disp_nt(dsize - 1 downto 0) 
                                                 & "0"  & next_y(2  downto 0);
-                        end if;--if (cur_x (2 downto 0) = "100" ) then
-                        if (cur_x (2 downto 0) = "110" ) then
+                        end if;--if (scrl_x (2 downto 0) = "100" ) then
+                        if (scrl_x (2 downto 0) = "110" ) then
                             ptn_l_we_n <= '0';
                         else
                             ptn_l_we_n <= '1';
                         end if;
 
                         ----fetch pattern table high byte.
-                        if (cur_x (2 downto 0) = "111" ) then
+                        if (scrl_x (2 downto 0) = "111" ) then
                             --vram addr is incremented every 8 cycle.
                             vram_addr <= "0" & ppu_ctrl(PPUBPA) & 
                                             disp_nt(dsize - 1 downto 0) 
                                                 & "0"  & next_y(2  downto 0) + "00000000001000";
-                        end if; --if (cur_x (2 downto 0) = "110" ) then
-                        if (cur_x (2 downto 0) = "000" and cur_x /= "000000000") then
+                        end if; --if (scrl_x (2 downto 0) = "110" ) then
+                        if (scrl_x (2 downto 0) = "000" and scrl_x /= "000000000") then
                             ptn_h_we_n <= '0';
                         else
                             ptn_h_we_n <= '1';
-                        end if;--if (cur_x (2 downto 0) = "001" ) then
+                        end if;--if (scrl_x (2 downto 0) = "001" ) then
                     end if; --if (cur_x <= conv_std_logic_vector(HSCAN, X_SIZE)) and
                 end if;--if (ppu_mask(PPUSBG) = '1') then
 

diff --git a/tools/test-image/sample1.asm b/tools/test-image/sample1.asm
index 11303f8..57bf476 100644 (file)
--- a/tools/test-image/sample1.asm
+++ b/tools/test-image/sample1.asm
@@ -124,7 +124,7 @@ at_st:
     ;;set scroll reg.\r
     lda #$03\r
     sta $2005\r
-    lda #$03\r
+    lda #$00\r
     sta $2005\r
 \r
     ;;show bg...\r