bsnes/sfc/coprocessor/obc1/obc1.cpp

80 lines
2.0 KiB
C++

#include <sfc/sfc.hpp>
namespace SuperFamicom {
#include "serialization.cpp"
OBC1 obc1;
auto OBC1::init() -> void {
}
auto OBC1::load() -> void {
}
auto OBC1::unload() -> void {
ram.reset();
}
auto OBC1::power() -> void {
}
auto OBC1::reset() -> void {
status.baseptr = (ramRead(0x1ff5) & 1) ? 0x1800 : 0x1c00;
status.address = (ramRead(0x1ff6) & 0x7f);
status.shift = (ramRead(0x1ff6) & 3) << 1;
}
auto OBC1::read(uint addr) -> uint8 {
addr &= 0x1fff;
switch(addr) {
case 0x1ff0: return ramRead(status.baseptr + (status.address << 2) + 0);
case 0x1ff1: return ramRead(status.baseptr + (status.address << 2) + 1);
case 0x1ff2: return ramRead(status.baseptr + (status.address << 2) + 2);
case 0x1ff3: return ramRead(status.baseptr + (status.address << 2) + 3);
case 0x1ff4: return ramRead(status.baseptr + (status.address >> 2) + 0x200);
}
return ramRead(addr);
}
auto OBC1::write(uint addr, uint8 data) -> void {
addr &= 0x1fff;
switch(addr) {
case 0x1ff0: ramWrite(status.baseptr + (status.address << 2) + 0, data); return;
case 0x1ff1: ramWrite(status.baseptr + (status.address << 2) + 1, data); return;
case 0x1ff2: ramWrite(status.baseptr + (status.address << 2) + 2, data); return;
case 0x1ff3: ramWrite(status.baseptr + (status.address << 2) + 3, data); return;
case 0x1ff4: {
uint8 temp = ramRead(status.baseptr + (status.address >> 2) + 0x200);
temp = (temp & ~(3 << status.shift)) | ((data & 3) << status.shift);
ramWrite(status.baseptr + (status.address >> 2) + 0x200, temp);
} return;
case 0x1ff5:
status.baseptr = (data & 1) ? 0x1800 : 0x1c00;
ramWrite(addr, data);
return;
case 0x1ff6:
status.address = (data & 0x7f);
status.shift = (data & 3) << 1;
ramWrite(addr, data);
return;
case 0x1ff7:
ramWrite(addr, data);
return;
}
return ramWrite(addr, data);
}
auto OBC1::ramRead(uint addr) -> uint8 {
return ram.read(addr & 0x1fff);
}
auto OBC1::ramWrite(uint addr, uint8 data) -> void {
ram.write(addr & 0x1fff, data);
}
}