bsnes/higan/sfc/cpu/mmio.cpp

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7.3 KiB
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auto CPU::apuPortRead(uint24 addr, uint8 data) -> uint8 {
synchronizeSMP();
return smp.portRead(addr.bits(0,1));
}
auto CPU::cpuPortRead(uint24 addr, uint8 data) -> uint8 {
addr &= 0xffff;
//WMDATA
if(addr == 0x2180) {
return bus.read(0x7e0000 | status.wram_addr++, regs.mdr);
}
//JOYSER0
//7-2 = MDR
//1-0 = Joypad serial data
if(addr == 0x4016) {
uint8 r = regs.mdr & 0xfc;
r |= device.controllerPort1->data();
return r;
}
//JOYSER1
if(addr == 0x4017) {
//7-5 = MDR
//4-2 = Always 1 (pins are connected to GND)
//1-0 = Joypad serial data
uint8 r = (regs.mdr & 0xe0) | 0x1c;
r |= device.controllerPort2->data();
return r;
}
//RDNMI
if(addr == 0x4210) {
//7 = NMI acknowledge
//6-4 = MDR
//3-0 = CPU (5a22) version
uint8 r = (regs.mdr & 0x70);
r |= (uint8)(rdnmi()) << 7;
r |= (cpu_version & 0x0f);
return r;
}
//TIMEUP
if(addr == 0x4211) {
//7 = IRQ acknowledge
//6-0 = MDR
uint8 r = (regs.mdr & 0x7f);
r |= (uint8)(timeup()) << 7;
return r;
}
//HVBJOY
if(addr == 0x4212) {
//7 = VBLANK acknowledge
//6 = HBLANK acknowledge
//5-1 = MDR
//0 = JOYPAD acknowledge
uint8 r = (regs.mdr & 0x3e);
if(status.auto_joypad_active) r |= 0x01;
if(hcounter() <= 2 || hcounter() >= 1096) r |= 0x40; //hblank
if(vcounter() >= (ppu.overscan() == false ? 225 : 240)) r |= 0x80; //vblank
return r;
}
//RDIO
if(addr == 0x4213) {
return status.pio;
}
//RDDIVL
if(addr == 0x4214) {
return status.rddiv.byte(0);
}
//RDDIVH
if(addr == 0x4215) {
return status.rddiv.byte(1);
}
//RDMPYL
if(addr == 0x4216) {
return status.rdmpy.byte(0);
}
//RDMPYH
if(addr == 0x4217) {
return status.rdmpy.byte(1);
}
if(addr == 0x4218) return status.joy1.byte(0); //JOY1L
if(addr == 0x4219) return status.joy1.byte(1); //JOY1H
if(addr == 0x421a) return status.joy2.byte(0); //JOY2L
if(addr == 0x421b) return status.joy2.byte(1); //JOY2H
if(addr == 0x421c) return status.joy3.byte(0); //JOY3L
if(addr == 0x421d) return status.joy3.byte(1); //JOY3H
if(addr == 0x421e) return status.joy4.byte(0); //JOY4L
if(addr == 0x421f) return status.joy4.byte(1); //JOY4H
return data;
}
auto CPU::dmaPortRead(uint24 addr, uint8 data) -> uint8 {
auto& channel = this->channel[addr.bits(4,6)];
addr &= 0xff0f;
//DMAPx
if(addr == 0x4300) return (
channel.direction << 7
| channel.indirect << 6
| channel.unused << 5
| channel.reverse_transfer << 4
| channel.fixed_transfer << 3
| channel.transfer_mode << 0
);
//BBADx
if(addr == 0x4301) return channel.dest_addr;
//A1TxL
if(addr == 0x4302) return channel.source_addr >> 0;
//A1TxH
if(addr == 0x4303) return channel.source_addr >> 8;
//A1Bx
if(addr == 0x4304) return channel.source_bank;
//DASxL -- union { uint16 transfer_size; uint16 indirect_addr; };
if(addr == 0x4305) return channel.transfer_size >> 0;
//DASxH -- union { uint16 transfer_size; uint16 indirect_addr; };
if(addr == 0x4306) return channel.transfer_size >> 8;
//DASBx
if(addr == 0x4307) return channel.indirect_bank;
//A2AxL
if(addr == 0x4308) return channel.hdma_addr >> 0;
//A2AxH
if(addr == 0x4309) return channel.hdma_addr >> 8;
//NTRLx
if(addr == 0x430a) return channel.line_counter;
//???
if(addr == 0x430b || addr == 0x430f) return channel.unknown;
return data;
}
auto CPU::apuPortWrite(uint24 addr, uint8 data) -> void {
synchronizeSMP();
return portWrite(addr.bits(0,1), data);
}
auto CPU::cpuPortWrite(uint24 addr, uint8 data) -> void {
addr &= 0xffff;
//WMDATA
if(addr == 0x2180) {
bus.write(0x7e0000 | status.wram_addr++, data);
}
//WMADDL
if(addr == 0x2181) {
status.wram_addr.bits(0,7) = data;
}
//WMADDM
if(addr == 0x2182) {
status.wram_addr.bits(8,15) = data;
}
//WMADDH
if(addr == 0x2183) {
status.wram_addr.bit(16) = data.bit(0);
}
//JOYSER0
if(addr == 0x4016) {
//bit 0 is shared between JOYSER0 and JOYSER1, therefore
//strobing $4016.d0 affects both controller port latches.
//$4017 bit 0 writes are ignored.
device.controllerPort1->latch(data.bit(0));
device.controllerPort2->latch(data.bit(0));
}
//NMITIMEN
if(addr == 0x4200) {
status.auto_joypad_poll = data.bit(0);
nmitimenUpdate(data);
}
//WRIO
if(addr == 0x4201) {
if(status.pio.bit(7) && !data.bit(7)) ppu.latch_counters();
status.pio = data;
}
//WRMPYA
if(addr == 0x4202) {
status.wrmpya = data;
}
//WRMPYB
if(addr == 0x4203) {
status.rdmpy = 0;
if(alu.mpyctr || alu.divctr) return;
status.wrmpyb = data;
status.rddiv = (status.wrmpyb << 8) | status.wrmpya;
alu.mpyctr = 8; //perform multiplication over the next eight cycles
alu.shift = status.wrmpyb;
}
//WRDIVL
if(addr == 0x4204) {
status.wrdiva.byte(0) = data;
}
//WRDIVH
if(addr == 0x4205) {
status.wrdiva.byte(1) = data;
}
//WRDIVB
if(addr == 0x4206) {
status.rdmpy = status.wrdiva;
if(alu.mpyctr || alu.divctr) return;
status.wrdivb = data;
alu.divctr = 16; //perform division over the next sixteen cycles
alu.shift = status.wrdivb << 16;
}
//HTIMEL
if(addr == 0x4207) {
status.hirq_pos.bits(0,7) = data;
}
//HTIMEH
if(addr == 0x4208) {
status.hirq_pos.bit(8) = data.bit(0);
}
//VTIMEL
if(addr == 0x4209) {
status.virq_pos.bits(0,7) = data;
}
//VTIMEH
if(addr == 0x420a) {
status.virq_pos.bit(8) = data;
}
//DMAEN
if(addr == 0x420b) {
for(auto n : range(8)) channel[n].dma_enabled = data.bit(n);
if(data) status.dma_pending = true;
}
//HDMAEN
if(addr == 0x420c) {
for(auto n : range(8)) channel[n].hdma_enabled = data.bit(n);
}
//MEMSEL
if(addr == 0x420d) {
status.rom_speed = data.bit(0) ? 6 : 8;
}
}
auto CPU::dmaPortWrite(uint24 addr, uint8 data) -> void {
auto& channel = this->channel[addr.bits(4,6)];
addr &= 0xff0f;
//DMAPx
if(addr == 0x4300) {
channel.direction = data & 0x80;
channel.indirect = data & 0x40;
channel.unused = data & 0x20;
channel.reverse_transfer = data & 0x10;
channel.fixed_transfer = data & 0x08;
channel.transfer_mode = data & 0x07;
}
//DDBADx
if(addr == 0x4301) {
channel.dest_addr = data;
}
//A1TxL
if(addr == 0x4302) {
channel.source_addr = (channel.source_addr & 0xff00) | (data << 0);
}
//A1TxH
if(addr == 0x4303) {
channel.source_addr = (channel.source_addr & 0x00ff) | (data << 8);
}
//A1Bx
if(addr == 0x4304) {
channel.source_bank = data;
}
//DASxL -- union { uint16 transfer_size; uint16 indirect_addr; };
if(addr == 0x4305) {
channel.transfer_size = (channel.transfer_size & 0xff00) | (data << 0);
}
//DASxH -- union { uint16 transfer_size; uint16 indirect_addr; };
if(addr == 0x4306) {
channel.transfer_size = (channel.transfer_size & 0x00ff) | (data << 8);
}
//DASBx
if(addr == 0x4307) {
channel.indirect_bank = data;
}
//A2AxL
if(addr == 0x4308) {
channel.hdma_addr = (channel.hdma_addr & 0xff00) | (data << 0);
}
//A2AxH
if(addr == 0x4309) {
channel.hdma_addr = (channel.hdma_addr & 0x00ff) | (data << 8);
}
//NTRLx
if(addr == 0x430a) {
channel.line_counter = data;
}
//???
if(addr == 0x430b || addr == 0x430f) {
channel.unknown = data;
}
}