chip8 draws in st7920 format now

chip8.sv

@@ -3,7 +3,7 @@ module chip8 (
     input wire rst_in
 );
 
-  bit vram[0:2047];
+  bit [7:0] vram[0:1023];
   bit [7:0] memory[0:4095];
 
   bit keyboard[15:0];

cpu.sv

@@ -6,7 +6,7 @@ module cpu (
     input wire [7:0] random_number,
     output int cycle_counter,
     output wire [15:0] program_counter,
-    output wire vram[0:2047],
+    output wire [7:0] vram[0:1023],
     output wire [7:0] sound_timer
 );
 
@@ -31,6 +31,36 @@ module cpu (
   logic [7:0] size;
   logic screen_pixel;
   logic [7:0] sprite_pixel;
+  
+  task write_pixels;
+    input [31:0] x;
+    input [31:0] y;
+
+    int i;
+     
+     begin
+         // bottom left
+         i = (y*128*2) + x*2 +127;
+
+         if (vram[i/8][7-(i%8)] == 1) begin
+           registers[15] = 1;
+         end
+
+         vram[i/8][7-(i%8)] ^= 1;      
+
+         // bottom right
+         i = (y*128*2) + x*2 +128;
+         vram[i/8][7-(i%8)] ^= 1;      
+
+         // top left
+         i = (y*128*2) + x*2-1;
+         vram[i/8][7-(i%8)] ^= 1;      
+
+         // top right
+         i = (y*128*2) + x*2;
+         vram[i/8][7-(i%8)] ^= 1;      
+     end
+  endtask
 
   always_ff @(negedge clk_in) begin
     if (system_ready) begin
@@ -187,14 +217,10 @@ module cpu (
           for (int r = 0; r < size; r++) begin
             for (int c = 0; c < 8; c++) begin
               if (r + y_cord >= 32 || x_cord + c >= 64) continue;
-              screen_pixel = vram[((r+y_cord)*64)+(x_cord+c)];
               sprite_pixel = memory[{16'h0000, index_reg}+r] & ('h80 >> c);
 
               if (|sprite_pixel) begin
-                if (screen_pixel == 1) begin
-                  registers[15] = 1;
-                end
-                vram[((r+y_cord)*64)+(x_cord+c)] ^= 1;
+                  write_pixels(x_cord + c, r+y_cord);
               end
             end
           end

gpu.sv

@@ -1,15 +1,17 @@
 module gpu (
-    input wire vram[0:2047]
+    input wire [7:0] vram[0:1023]
 );
 
   import "DPI-C" function void init_screen();
-  import "DPI-C" function void draw_screen(logic vram[0:2047]);
+  import "DPI-C" function void draw_screen(logic [7:0] vram[0:1023]);
 
   initial begin
     init_screen();
+
   end
 
+
   always_comb begin
-    draw_screen(vram);
+      draw_screen(vram);
   end
 endmodule

yayacemu.cpp

@@ -10,8 +10,8 @@
 #include <iostream>
 #include <memory.h>
 
-#define SCREEN_WIDTH 64
-#define SCREEN_HEIGHT 32
+#define SCREEN_WIDTH 128 
+#define SCREEN_HEIGHT 64 
 #define EMULATION_HZ 2000
 
 FILE *rom_file;
@@ -41,10 +41,14 @@ void set_beep(const svBit beep) {
     SDL_SetTextureColorMod(texture, 255, 255, 255);
 }
 
-void draw_screen(const svLogic *vram) {
+void draw_screen(const svLogicVecVal *vram) {
   uint32_t *screen = (uint32_t *)malloc(SCREEN_WIDTH * SCREEN_HEIGHT * 32);
-  for (int i = 0; i < SCREEN_WIDTH * SCREEN_HEIGHT; i++) {
-    screen[i] = vram[i] == 1 ? 0xFFFFFFFF : 0x00000000;
+  for (int i = 0; i < 1024; i++) {
+      uint8_t line_byte = (uint8_t) vram[i].aval;
+      for (int j = 0; j < 8; j++) {
+            uint8_t pixel_val = (line_byte >> (7-j)) & 1;
+            screen[(i*8) + j] = pixel_val == 1 ? 0xFFFFFFFF : 0x00000000;
+      }
   }
   SDL_UpdateTexture(texture, NULL, screen, sizeof(screen[0]) * SCREEN_WIDTH);
   SDL_RenderClear(renderer);