bsnes/src/cpu/scpu/mmio/mmio.cpp

598 lines
14 KiB
C++

uint8 sCPU::pio_status() {
return status.pio;
}
/*****
* WRAM data registers
*****/
//WMDATA
uint8 sCPU::mmio_r2180() {
uint8 r = r_mem->read(0x7e0000 | status.wram_addr++);
status.wram_addr &= 0x01ffff;
return r;
}
//WMDATA
void sCPU::mmio_w2180(uint8 data) {
r_mem->write(0x7e0000 | status.wram_addr++, data);
status.wram_addr &= 0x01ffff;
}
//WMADDL
void sCPU::mmio_w2181(uint8 data) {
status.wram_addr = (status.wram_addr & 0xffff00) | (data);
status.wram_addr &= 0x01ffff;
}
//WMADDM
void sCPU::mmio_w2182(uint8 data) {
status.wram_addr = (status.wram_addr & 0xff00ff) | (data << 8);
status.wram_addr &= 0x01ffff;
}
//WMADDH
void sCPU::mmio_w2183(uint8 data) {
status.wram_addr = (status.wram_addr & 0x00ffff) | (data << 16);
status.wram_addr &= 0x01ffff;
}
/*****
* Joypad registers
*****/
//TODO: test whether strobe latch of zero returns
//realtime or buffered status of joypadN.b
//JOYSER0
//7-2 = MDR
//1-0 = Joypad serial data
uint8 sCPU::mmio_r4016() {
uint8 r = regs.mdr & 0xfc;
r |= status.joypad1_bits & 1;
if(status.joypad_strobe_latch == 0) {
status.joypad1_bits >>= 1;
status.joypad1_bits |= 0x8000;
}
return r;
}
//JOYSER1
//7-5 = MDR
//4-2 = Always 1 (pins are connected to GND)
//1-0 = Joypad serial data
uint8 sCPU::mmio_r4017() {
uint8 r = (regs.mdr & 0xe0) | 0x1c;
r |= status.joypad2_bits & 1;
if(status.joypad_strobe_latch == 0) {
status.joypad2_bits >>= 1;
status.joypad2_bits |= 0x8000;
}
return r;
}
//TODO: handle reads during joypad polling (v=225-227)
uint8 sCPU::mmio_r4218() { return status.joy1l; } //JOY1L
uint8 sCPU::mmio_r4219() { return status.joy1h; } //JOY1H
uint8 sCPU::mmio_r421a() { return status.joy2l; } //JOY2L
uint8 sCPU::mmio_r421b() { return status.joy2h; } //JOY2H
uint8 sCPU::mmio_r421c() { return status.joy3l; } //JOY3L
uint8 sCPU::mmio_r421d() { return status.joy3h; } //JOY3H
uint8 sCPU::mmio_r421e() { return status.joy4l; } //JOY4L
uint8 sCPU::mmio_r421f() { return status.joy4h; } //JOY4H
//JOYSER0
//bit 0 is shared between JOYSER0 and JOYSER1, therefore
//strobing $4016.d0 affects both controller port latches.
//$4017 bit 0 writes are ignored.
void sCPU::mmio_w4016(uint8 data) {
status.joypad_strobe_latch = bool(data & 1);
if(status.joypad_strobe_latch == 1) {
run_manual_joypad_poll();
}
}
/*****
* NMI / IRQ registers
*****/
//RDNMI
//7 = NMI acknowledge
//6-4 = MDR
//3-0 = CPU (5a22) version
uint8 sCPU::mmio_r4210() {
uint8 r = (regs.mdr & 0x70);
r |= uint8(!status.nmi_read) << 7;
if(!nmi_read_pos_match(0) && !nmi_read_pos_match(2)) {
status.nmi_read = 1;
}
r |= (cpu_version & 0x0f);
return r;
}
//TIMEUP
//7 = IRQ acknowledge
//6-0 = MDR
uint8 sCPU::mmio_r4211() {
uint8 r = (regs.mdr & 0x7f);
r |= uint8(!status.irq_read) << 7;
if(!irq_read_pos_match(0) && !irq_read_pos_match(2)) {
status.irq_read = 1;
status.irq_line = 1;
status.irq_transition = 0;
}
return r;
}
//HVBJOY
//7 = VBLANK acknowledge
//6 = HBLANK acknowledge
//5-1 = MDR
//0 = JOYPAD acknowledge
uint8 sCPU::mmio_r4212() {
uint8 r = (regs.mdr & 0x3e);
uint16 vs = !overscan() ? 225 : 240;
//auto joypad polling
if(status.vcounter >= vs && status.vcounter <= (vs + 2))r |= 0x01;
//hblank
if(status.hclock <= 2 || status.hclock >= 1096)r |= 0x40;
//vblank
if(status.vcounter >= vs)r |= 0x80;
return r;
}
//NMITIMEN
void sCPU::mmio_w4200(uint8 data) {
status.nmi_enabled = bool(data & 0x80);
status.virq_enabled = bool(data & 0x20);
status.hirq_enabled = bool(data & 0x10);
status.auto_joypad_poll = bool(data & 0x01);
//if(!status.nmi_enabled)status.nmi_read=1;
if(status.nmi_read == 0) {
if(status.nmi_line == 1 && !status.nmi_enabled == 0) {
status.nmi_transition = 1;
}
status.nmi_line = !status.nmi_enabled;
}
if(status.virq_enabled == false && status.hirq_enabled == false) {
status.irq_line = 1;
status.irq_read = 1;
status.irq_transition = 0;
}
update_interrupts();
set_irq_delay(2);
}
//HTIMEL
void sCPU::mmio_w4207(uint8 data) {
status.hirq_pos = (status.hirq_pos & ~0xff) | (data);
status.hirq_pos &= 0x01ff;
update_interrupts();
}
//HTIMEH
void sCPU::mmio_w4208(uint8 data) {
status.hirq_pos = (status.hirq_pos & 0xff) | (data << 8);
status.hirq_pos &= 0x01ff;
update_interrupts();
}
//VTIMEL
void sCPU::mmio_w4209(uint8 data) {
status.virq_pos = (status.virq_pos & ~0xff) | (data);
status.virq_pos &= 0x01ff;
update_interrupts();
}
//VTIMEH
void sCPU::mmio_w420a(uint8 data) {
status.virq_pos = (status.virq_pos & 0xff) | (data << 8);
status.virq_pos &= 0x01ff;
update_interrupts();
}
/*****
* I/O registers
****/
//RDIO
uint8 sCPU::mmio_r4213() {
return status.pio;
}
//WRIO
void sCPU::mmio_w4201(uint8 data) {
if((status.pio & 0x80) && !(data & 0x80)) {
r_ppu->latch_counters();
}
status.pio = data;
}
/*****
* Math registers (multiplication and division)
*****/
//RDDIVL
uint8 sCPU::mmio_r4214() {
return status.r4214;
}
//RDDIVH
uint8 sCPU::mmio_r4215() {
return status.r4214 >> 8;
}
//RDMPYL
uint8 sCPU::mmio_r4216() {
return status.r4216;
}
//RDMPYH
uint8 sCPU::mmio_r4217() {
return status.r4216 >> 8;
}
//WRMPYA
void sCPU::mmio_w4202(uint8 data) {
status.mul_a = data;
}
//WRMPYB
void sCPU::mmio_w4203(uint8 data) {
status.mul_b = data;
status.r4216 = status.mul_a * status.mul_b;
}
//WRDIVL
void sCPU::mmio_w4204(uint8 data) {
status.div_a = (status.div_a & 0xff00) | (data);
}
//WRDIVH
void sCPU::mmio_w4205(uint8 data) {
status.div_a = (status.div_a & 0x00ff) | (data << 8);
}
//WRDIVB
void sCPU::mmio_w4206(uint8 data) {
status.div_b = data;
status.r4214 = (status.div_b) ? status.div_a / status.div_b : 0xffff;
status.r4216 = (status.div_b) ? status.div_a % status.div_b : status.div_a;
}
/*****
* DMA / HDMA registers
*****/
//DMAPx
uint8 sCPU::mmio_r43x0(uint8 i) {
return channel[i].dmap;
}
//BBADx
uint8 sCPU::mmio_r43x1(uint8 i) {
return channel[i].destaddr;
}
//A1TxL
uint8 sCPU::mmio_r43x2(uint8 i) {
return channel[i].srcaddr;
}
//A1TxH
uint8 sCPU::mmio_r43x3(uint8 i) {
return channel[i].srcaddr >> 8;
}
//A1Bx
uint8 sCPU::mmio_r43x4(uint8 i) {
return channel[i].srcbank;
}
//DASxL
//union { uint16 xfersize; uint16 hdma_iaddr; };
uint8 sCPU::mmio_r43x5(uint8 i) {
return channel[i].xfersize;
}
//DASxH
//union { uint16 xfersize; uint16 hdma_iaddr; };
uint8 sCPU::mmio_r43x6(uint8 i) {
return channel[i].xfersize >> 8;
}
//DASBx
uint8 sCPU::mmio_r43x7(uint8 i) {
return channel[i].hdma_ibank;
}
//A2AxL
uint8 sCPU::mmio_r43x8(uint8 i) {
return channel[i].hdma_addr;
}
//A2AxH
uint8 sCPU::mmio_r43x9(uint8 i) {
return channel[i].hdma_addr >> 8;
}
//NTRLx
uint8 sCPU::mmio_r43xa(uint8 i) {
return channel[i].hdma_line_counter;
}
//???
uint8 sCPU::mmio_r43xb(uint8 i) {
return channel[i].unknown;
}
//DMAEN
//Note: DMA enable does not disable active HDMA channels
void sCPU::mmio_w420b(uint8 data) {
for(int i = 0; i < 8; i++) {
channel[i].dma_enabled = bool(data & (1 << i));
}
if(data)dma_run(); //temporary
}
//HDMAEN
void sCPU::mmio_w420c(uint8 data) {
for(int i = 0; i < 8; i++) {
channel[i].hdma_enabled = bool(data & (1 << i));
}
}
//MEMSEL
void sCPU::mmio_w420d(uint8 data) {
r_mem->set_speed(data & 1);
}
//DMAPx
void sCPU::mmio_w43x0(uint8 i, uint8 data) {
channel[i].dmap = data;
channel[i].direction = bool(data & 0x80);
channel[i].hdma_indirect = bool(data & 0x40);
channel[i].reversexfer = bool(data & 0x10);
channel[i].fixedxfer = bool(data & 0x08);
channel[i].xfermode = data & 7;
}
//DDBADx
void sCPU::mmio_w43x1(uint8 i, uint8 data) {
channel[i].destaddr = data;
}
//A1TxL
void sCPU::mmio_w43x2(uint8 i, uint8 data) {
channel[i].srcaddr = (channel[i].srcaddr & 0xff00) | (data);
}
//A1TxH
void sCPU::mmio_w43x3(uint8 i, uint8 data) {
channel[i].srcaddr = (channel[i].srcaddr & 0x00ff) | (data << 8);
}
//A1Bx
void sCPU::mmio_w43x4(uint8 i, uint8 data) {
channel[i].srcbank = data;
}
//DASxL
//union { uint16 xfersize; uint16 hdma_iaddr; };
void sCPU::mmio_w43x5(uint8 i, uint8 data) {
channel[i].xfersize = (channel[i].xfersize & 0xff00) | (data);
}
//DASxH
//union { uint16 xfersize; uint16 hdma_iaddr; };
void sCPU::mmio_w43x6(uint8 i, uint8 data) {
channel[i].xfersize = (channel[i].xfersize & 0x00ff) | (data << 8);
}
//DASBx
void sCPU::mmio_w43x7(uint8 i, uint8 data) {
channel[i].hdma_ibank = data;
}
//A2AxL
void sCPU::mmio_w43x8(uint8 i, uint8 data) {
channel[i].hdma_addr = (channel[i].hdma_addr & 0xff00) | (data);
}
//A2AxH
void sCPU::mmio_w43x9(uint8 i, uint8 data) {
channel[i].hdma_addr = (channel[i].hdma_addr & 0x00ff) | (data << 8);
}
//NTRLx
void sCPU::mmio_w43xa(uint8 i, uint8 data) {
channel[i].hdma_line_counter = data;
}
//???
void sCPU::mmio_w43xb(uint8 i, uint8 data) {
channel[i].unknown = data;
}
/*****
* reset / read / write
*****/
void sCPU::mmio_power() {
}
void sCPU::mmio_reset() {
//$2181-$2183
status.wram_addr = 0x000000;
//$4016-$4017
status.joypad_strobe_latch = 0;
status.joypad1_bits = ~0;
status.joypad2_bits = ~0;
//$4200
status.nmi_enabled = false;
status.hirq_enabled = false;
status.virq_enabled = false;
status.auto_joypad_poll = false;
//$4201
status.pio = 0xff;
//$4202-$4203
status.mul_a = 0xff;
status.mul_b = 0xff;
//$4204-$4206
status.div_a = 0xffff;
status.div_b = 0xff;
//$4207-$420a
status.hirq_pos = 0x01ff;
status.virq_pos = 0x01ff;
//$4214-$4217
status.r4214 = 0x0000;
status.r4216 = 0x0000;
//$4218-$421f
status.joy1l = 0x00;
status.joy1h = 0x00;
status.joy2l = 0x00;
status.joy2h = 0x00;
status.joy3l = 0x00;
status.joy3h = 0x00;
status.joy4l = 0x00;
status.joy4h = 0x00;
}
uint8 sCPU::mmio_read(uint16 addr) {
//APU
if((addr & 0xffc0) == 0x2140) { //$2140-$217f
#ifdef FAVOR_SPEED
co_return();
#endif
return r_apu->port_read(addr & 3);
}
//DMA
if((addr & 0xff80) == 0x4300) { //$4300-$437f
uint i = (addr >> 4) & 7;
switch(addr & 0xf) {
case 0x0: return mmio_r43x0(i);
case 0x1: return mmio_r43x1(i);
case 0x2: return mmio_r43x2(i);
case 0x3: return mmio_r43x3(i);
case 0x4: return mmio_r43x4(i);
case 0x5: return mmio_r43x5(i);
case 0x6: return mmio_r43x6(i);
case 0x7: return mmio_r43x7(i);
case 0x8: return mmio_r43x8(i);
case 0x9: return mmio_r43x9(i);
case 0xa: return mmio_r43xa(i);
case 0xb: return mmio_r43xb(i);
case 0xc: return regs.mdr; //unmapped
case 0xd: return regs.mdr; //unmapped
case 0xe: return regs.mdr; //unmapped
case 0xf: return mmio_r43xb(i); //mirror of $43xb
}
}
switch(addr) {
case 0x2180: return mmio_r2180();
case 0x4016: return mmio_r4016();
case 0x4017: return mmio_r4017();
case 0x4210: return mmio_r4210();
case 0x4211: return mmio_r4211();
case 0x4212: return mmio_r4212();
case 0x4213: return mmio_r4213();
case 0x4214: return mmio_r4214();
case 0x4215: return mmio_r4215();
case 0x4216: return mmio_r4216();
case 0x4217: return mmio_r4217();
case 0x4218: return mmio_r4218();
case 0x4219: return mmio_r4219();
case 0x421a: return mmio_r421a();
case 0x421b: return mmio_r421b();
case 0x421c: return mmio_r421c();
case 0x421d: return mmio_r421d();
case 0x421e: return mmio_r421e();
case 0x421f: return mmio_r421f();
}
return regs.mdr;
}
void sCPU::mmio_write(uint16 addr, uint8 data) {
//APU
if((addr & 0xffc0) == 0x2140) { //$2140-$217f
#ifdef FAVOR_SPEED
co_return();
#endif
port_write(addr & 3, data);
return;
}
//DMA
if((addr & 0xff80) == 0x4300) { //$4300-$437f
uint i = (addr >> 4) & 7;
switch(addr & 0xf) {
case 0x0: mmio_w43x0(i, data); return;
case 0x1: mmio_w43x1(i, data); return;
case 0x2: mmio_w43x2(i, data); return;
case 0x3: mmio_w43x3(i, data); return;
case 0x4: mmio_w43x4(i, data); return;
case 0x5: mmio_w43x5(i, data); return;
case 0x6: mmio_w43x6(i, data); return;
case 0x7: mmio_w43x7(i, data); return;
case 0x8: mmio_w43x8(i, data); return;
case 0x9: mmio_w43x9(i, data); return;
case 0xa: mmio_w43xa(i, data); return;
case 0xb: mmio_w43xb(i, data); return;
case 0xc: return; //unmapped
case 0xd: return; //unmapped
case 0xe: return; //unmapped
case 0xf: mmio_w43xb(i, data); return; //mirror of $43xb
}
}
switch(addr) {
case 0x2180: mmio_w2180(data); return;
case 0x2181: mmio_w2181(data); return;
case 0x2182: mmio_w2182(data); return;
case 0x2183: mmio_w2183(data); return;
case 0x4016: mmio_w4016(data); return;
case 0x4017: return; //unmapped
case 0x4200: mmio_w4200(data); return;
case 0x4201: mmio_w4201(data); return;
case 0x4202: mmio_w4202(data); return;
case 0x4203: mmio_w4203(data); return;
case 0x4204: mmio_w4204(data); return;
case 0x4205: mmio_w4205(data); return;
case 0x4206: mmio_w4206(data); return;
case 0x4207: mmio_w4207(data); return;
case 0x4208: mmio_w4208(data); return;
case 0x4209: mmio_w4209(data); return;
case 0x420a: mmio_w420a(data); return;
case 0x420b: mmio_w420b(data); return;
case 0x420c: mmio_w420c(data); return;
case 0x420d: mmio_w420d(data); return;
}
}