bsnes/higan/sfc/chip/sa1/memory/memory.cpp

279 lines
8.0 KiB
C++
Executable File

#ifdef SA1_CPP
uint8 SA1::bus_read(unsigned addr) {
if((addr & 0x40fe00) == 0x002200) { //$00-3f|80-bf:2200-23ff
return mmio_read(addr);
}
if((addr & 0x408000) == 0x008000) { //$00-3f|80-bf:8000-ffff
return mmcrom_read(addr);
}
if((addr & 0xc00000) == 0xc00000) { //$c0-ff:0000-ffff
return mmcrom_read(addr);
}
if((addr & 0x40e000) == 0x006000) { //$00-3f|80-bf:6000-7fff
return mmc_sa1_read(addr);
}
if((addr & 0x40f800) == 0x000000) { //$00-3f|80-bf:0000-07ff
synchronize_cpu();
return iram.read(addr & 2047);
}
if((addr & 0x40f800) == 0x003000) { //$00-3f|80-bf:3000-37ff
synchronize_cpu();
return iram.read(addr & 2047);
}
if((addr & 0xf00000) == 0x400000) { //$40-4f:0000-ffff
synchronize_cpu();
return bwram.read(addr & (bwram.size() - 1));
}
if((addr & 0xf00000) == 0x600000) { //$60-6f:0000-ffff
synchronize_cpu();
return bitmap_read(addr & 0x0fffff);
}
}
void SA1::bus_write(unsigned addr, uint8 data) {
if((addr & 0x40fe00) == 0x002200) { //$00-3f|80-bf:2200-23ff
return mmio_write(addr, data);
}
if((addr & 0x40e000) == 0x006000) { //$00-3f|80-bf:6000-7fff
return mmc_sa1_write(addr, data);
}
if((addr & 0x40f800) == 0x000000) { //$00-3f|80-bf:0000-07ff
synchronize_cpu();
return iram.write(addr & 2047, data);
}
if((addr & 0x40f800) == 0x003000) { //$00-3f|80-bf:3000-37ff
synchronize_cpu();
return iram.write(addr & 2047, data);
}
if((addr & 0xf00000) == 0x400000) { //$40-4f:0000-ffff
synchronize_cpu();
return bwram.write(addr & (bwram.size() - 1), data);
}
if((addr & 0xf00000) == 0x600000) { //$60-6f:0000-ffff
synchronize_cpu();
return bitmap_write(addr & 0x0fffff, data);
}
}
//$230c (VDPL), $230d (VDPH) use this bus to read variable-length data.
//this is used both to keep VBR-reads from accessing MMIO registers, and
//to avoid syncing the S-CPU and SA-1*; as both chips are able to access
//these ports.
uint8 SA1::vbr_read(unsigned addr) {
if((addr & 0x408000) == 0x008000) { //$00-3f|80-bf:8000-ffff
return mmcrom_read(addr);
}
if((addr & 0xc00000) == 0xc00000) { //$c0-ff:0000-ffff
return mmcrom_read(addr);
}
if((addr & 0x40e000) == 0x006000) { //$00-3f|80-bf:6000-7fff
return bwram.read(addr & (bwram.size() - 1));
}
if((addr & 0xf00000) == 0x400000) { //$40-4f:0000-ffff
return bwram.read(addr & (bwram.size() - 1));
}
if((addr & 0x40f800) == 0x000000) { //$00-3f|80-bf:0000-07ff
return iram.read(addr & 2047);
}
if((addr & 0x40f800) == 0x003000) { //$00-3f|80-bf:3000-37ff
return iram.read(addr & 0x2047);
}
}
//ROM, I-RAM and MMIO registers are accessed at ~10.74MHz (2 clock ticks)
//BW-RAM is accessed at ~5.37MHz (4 clock ticks)
//tick() == 2 clock ticks
//note: bus conflict delays are not emulated at this time
void SA1::op_io() {
tick();
}
uint8 SA1::op_read(unsigned addr) {
tick();
if(((addr & 0x40e000) == 0x006000) || ((addr & 0xd00000) == 0x400000)) tick();
return bus_read(addr);
}
void SA1::op_write(unsigned addr, uint8 data) {
tick();
if(((addr & 0x40e000) == 0x006000) || ((addr & 0xd00000) == 0x400000)) tick();
bus_write(addr, data);
}
uint8 SA1::mmcrom_read(unsigned addr) {
if((addr & 0xffffe0) == 0x00ffe0) {
if(addr == 0xffea && sa1.mmio.cpu_nvsw) return sa1.mmio.snv >> 0;
if(addr == 0xffeb && sa1.mmio.cpu_nvsw) return sa1.mmio.snv >> 8;
if(addr == 0xffee && sa1.mmio.cpu_ivsw) return sa1.mmio.siv >> 0;
if(addr == 0xffef && sa1.mmio.cpu_ivsw) return sa1.mmio.siv >> 8;
}
static auto read = [](unsigned addr) {
return sa1.rom.read(bus.mirror(addr, sa1.rom.size()));
};
if((addr & 0xe08000) == 0x008000) { //$00-1f:8000-ffff
addr = ((addr & 0x1f0000) >> 1) | (addr & 0x007fff);
if(mmio.cbmode == 0) return read(0x000000 | addr);
return read((mmio.cb << 20) | addr);
}
if((addr & 0xe08000) == 0x208000) { //$20-3f:8000-ffff
addr = ((addr & 0x1f0000) >> 1) | (addr & 0x007fff);
if(mmio.dbmode == 0) return read(0x100000 | addr);
return read((mmio.db << 20) | addr);
}
if((addr & 0xe08000) == 0x808000) { //$80-9f:8000-ffff
addr = ((addr & 0x1f0000) >> 1) | (addr & 0x007fff);
if(mmio.ebmode == 0) return read(0x200000 | addr);
return read((mmio.eb << 20) | addr);
}
if((addr & 0xe08000) == 0xa08000) { //$a0-bf:8000-ffff
addr = ((addr & 0x1f0000) >> 1) | (addr & 0x007fff);
if(mmio.fbmode == 0) return read(0x300000 | addr);
return read((mmio.fb << 20) | addr);
}
if((addr & 0xf00000) == 0xc00000) { //$c0-cf:0000-ffff
return read((mmio.cb << 20) | (addr & 0x0fffff));
}
if((addr & 0xf00000) == 0xd00000) { //$d0-df:0000-ffff
return read((mmio.db << 20) | (addr & 0x0fffff));
}
if((addr & 0xf00000) == 0xe00000) { //$e0-ef:0000-ffff
return read((mmio.eb << 20) | (addr & 0x0fffff));
}
if((addr & 0xf00000) == 0xf00000) { //$f0-ff:0000-ffff
return read((mmio.fb << 20) | (addr & 0x0fffff));
}
return 0x00;
}
void SA1::mmcrom_write(unsigned addr, uint8 data) {
}
uint8 SA1::mmcbwram_read(unsigned addr) {
if((addr & 0x40e000) == 0x006000) { //$00-3f|80-bf:6000-7fff
cpu.synchronize_coprocessors();
addr = bus.mirror(mmio.sbm * 0x2000 + (addr & 0x1fff), cpubwram.size());
return cpubwram.read(addr);
}
if((addr & 0xf00000) == 0x400000) { //$40-4f:0000-ffff
return cpubwram.read(addr & 0x0fffff);
}
return cpu.regs.mdr;
}
void SA1::mmcbwram_write(unsigned addr, uint8 data) {
if((addr & 0x40e000) == 0x006000) { //$00-3f|80-bf:6000-7fff
cpu.synchronize_coprocessors();
addr = bus.mirror(mmio.sbm * 0x2000 + (addr & 0x1fff), cpubwram.size());
return cpubwram.write(addr, data);
}
if((addr & 0xf00000) == 0x400000) { //$40-4f:0000-ffff
return cpubwram.write(addr & 0x0fffff, data);
}
}
uint8 SA1::mmc_sa1_read(unsigned addr) {
synchronize_cpu();
if(mmio.sw46 == 0) {
//$40-43:0000-ffff x 32 projection
addr = bus.mirror((mmio.cbm & 0x1f) * 0x2000 + (addr & 0x1fff), bwram.size());
return bwram.read(addr);
} else {
//$60-6f:0000-ffff x 128 projection
addr = bus.mirror(mmio.cbm * 0x2000 + (addr & 0x1fff), 0x100000);
return bitmap_read(addr);
}
}
void SA1::mmc_sa1_write(unsigned addr, uint8 data) {
synchronize_cpu();
if(mmio.sw46 == 0) {
//$40-43:0000-ffff x 32 projection
addr = bus.mirror((mmio.cbm & 0x1f) * 0x2000 + (addr & 0x1fff), bwram.size());
bwram.write(addr, data);
} else {
//$60-6f:0000-ffff x 128 projection
addr = bus.mirror(mmio.cbm * 0x2000 + (addr & 0x1fff), 0x100000);
bitmap_write(addr, data);
}
}
uint8 SA1::bitmap_read(unsigned addr) {
if(mmio.bbf == 0) {
//4bpp
unsigned shift = addr & 1;
addr = (addr >> 1) & (bwram.size() - 1);
switch(shift) { default:
case 0: return (bwram.read(addr) >> 0) & 15;
case 1: return (bwram.read(addr) >> 4) & 15;
}
} else {
//2bpp
unsigned shift = addr & 3;
addr = (addr >> 2) & (bwram.size() - 1);
switch(shift) { default:
case 0: return (bwram.read(addr) >> 0) & 3;
case 1: return (bwram.read(addr) >> 2) & 3;
case 2: return (bwram.read(addr) >> 4) & 3;
case 3: return (bwram.read(addr) >> 6) & 3;
}
}
}
void SA1::bitmap_write(unsigned addr, uint8 data) {
if(mmio.bbf == 0) {
//4bpp
unsigned shift = addr & 1;
addr = (addr >> 1) & (bwram.size() - 1);
switch(shift) { default:
case 0: data = (bwram.read(addr) & 0xf0) | ((data & 15) << 0); break;
case 1: data = (bwram.read(addr) & 0x0f) | ((data & 15) << 4); break;
}
} else {
//2bpp
unsigned shift = addr & 3;
addr = (addr >> 2) & (bwram.size() - 1);
switch(shift) { default:
case 0: data = (bwram.read(addr) & 0xfc) | ((data & 3) << 0); break;
case 1: data = (bwram.read(addr) & 0xf3) | ((data & 3) << 2); break;
case 2: data = (bwram.read(addr) & 0xcf) | ((data & 3) << 4); break;
case 3: data = (bwram.read(addr) & 0x3f) | ((data & 3) << 6); break;
}
}
bwram.write(addr, data);
}
#endif