diff options
Diffstat (limited to 'memory.c')
| -rw-r--r-- | memory.c | 10 |
1 files changed, 10 insertions, 0 deletions
@@ -8,15 +8,19 @@ static uint8_t memory_read(struct nes_state *restrict state, uint32_t offset) { if(LIKELY(offset < 0x2000)) { return state->ram[offset & 0x07ff]; + } else if(offset < 0x4000) { return ppu_read(state, offset); + } else if(offset == 0x4016 || offset == 0x4017) { uint32_t index = offset & 1; uint8_t value = (state->input_latch[index] >> state->input_bit[index]) & 1; state->input_bit[index]++; return value | 0x40; // Bit 6 open bus high, bit 7 low + } else if(LIKELY(offset >= 0x6000)) { return state->mapper.prg_read(state, offset); + } return 0; } @@ -28,10 +32,13 @@ static void memory_write(struct nes_state *restrict state, uint32_t offset, uint if(LIKELY(offset < 0x2000)) { state->ram[offset & 0x07ff] = value; + } else if(offset < 0x4000) { ppu_write(state, offset, value); + } else if(offset == 0x4014) { ppu_dma_4014(state, value); + } else if(offset == 0x4016) { uint8_t prev = state->input_strobe; state->input_strobe = value & 1; @@ -43,6 +50,7 @@ static void memory_write(struct nes_state *restrict state, uint32_t offset, uint state->input_bit[0] = 0; state->input_bit[1] = 0; } + } else if(offset >= 0x6000) { state->mapper.prg_write(state, offset, value); } @@ -53,8 +61,10 @@ static uint8_t memory_read_dma(struct nes_state *restrict state, uint32_t offset // Do not tick CPU/PPU/APU — caller handles timing if(LIKELY(offset < 0x2000)) { return state->ram[offset & 0x07ff]; + } else if(offset >= 0x6000) { return state->mapper.prg_read(state, offset); + } return 0; } |