Again read write implementation

somelun · Sep 10, 2024 · 41ac332 · 41ac332
1 parent 9ecaa74
commit 41ac332
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Showing 2 changed files with 23 additions and 8 deletions.
diff --git a/src/bus.zig b/src/bus.zig
@@ -67,7 +67,7 @@ pub const Bus = struct {
 
     pub fn init() Bus {
         var bus: Bus = Bus{};
-        bus.ppu = PPU.init(bus.rom.chr_rom, bus.rom.screen_mirroring);
+        bus.ppu = PPU.init();
 
         return bus;
     }
@@ -79,6 +79,7 @@ pub const Bus = struct {
         self.rom = Rom.init(rom_path) catch {
             return false;
         };
+        self.ppu.updateRomData(self.rom.chr_rom, self.rom.screen_mirroring);
 
         return true;
     }
@@ -100,9 +101,14 @@ pub const Bus = struct {
                 data = self.wram[address & 0x07FF];
             },
 
+            // read from PPU Data register
+            0x2007 => {
+                data = self.ppu.readData(address);
+            },
+
             // PPU memory range also with mirroring
             PPU_REG_BEGIN...PPU_REG_END => {
-                data = self.read8(address & 0x2007);
+                data = self.ppu.readData(address & 0x2007);
             },
 
             // ROM memory range
@@ -123,7 +129,13 @@ pub const Bus = struct {
                 self.wram[address & 0x07FF] = data;
             },
 
+            // Controll, Address, Data PPu registers
+            0x2000, 0x2006, 0x2007 => {
+                self.ppu.writeData(data);
+            },
+
             PPU_REG_BEGIN...PPU_REG_END => {
+                // for now calling self with mirrored address
                 self.write8(address & 0x2007, data);
             },
 

diff --git a/src/ppu.zig b/src/ppu.zig
@@ -55,17 +55,20 @@ pub const PPU = struct {
 
     internal_buffer: u8 = 0,
 
-    pub fn init(chr_rom: []u8, mirroring: Mirroring) PPU {
+    pub fn init() PPU {
         var ppu = PPU{};
 
-        ppu.chr_rom = chr_rom;
-        ppu.mirroring = mirroring;
         ppu.addressRegister = AddressRegister.init();
         ppu.controllerRegister = ControllerRegister.init();
 
         return ppu;
     }
 
+    pub fn updateRomData(self: *PPU, chr_rom: []u8, mirroring: Mirroring) void {
+        self.chr_rom = chr_rom;
+        self.mirroring = mirroring;
+    }
+
     // instead of implementing PPU Data Register (0x2007) we just have this function
     pub fn readData(self: *PPU) u8 {
         const address: u16 = self.addressRegister.get();
@@ -128,9 +131,9 @@ pub const PPU = struct {
                 self.addressRegister.increment(self.controllerRegister.VRAMAddressIncrement());
             },
 
-            // 0x2000...0x2FFF => {
-            //     self.vram[self.mirrorVRAMAddress(address)] = value;
-            // },
+            0x2000...0x2FFF => {
+                self.vram[self.mirrorVRAMAddress(address)] = value;
+            },
 
             0x3F00...0x3FFF => {
                 // Addresses 0x3F10/0x3F14/0x3F18/0x3F1C are mirrors of $3F00/$3F04/$3F08/$3F0C.