bsnes/sfc/chip/spc7110/data.cpp

63 lines
2.0 KiB
C++

#ifdef SPC7110_CPP
uint8 SPC7110::datarom_read(unsigned addr) {
unsigned size = 1 << (r4834 & 3); //size in MB
unsigned mask = 0x100000 * size - 1;
unsigned offset = addr & mask;
if((r4834 & 3) != 3 && (addr & 0x400000)) return 0x00;
return drom.read(Bus::mirror(offset, drom.size()));
}
unsigned SPC7110::data_offset() { return r4811 | r4812 << 8 | r4813 << 16; }
unsigned SPC7110::data_adjust() { return r4814 | r4815 << 8; }
unsigned SPC7110::data_stride() { return r4816 | r4817 << 8; }
void SPC7110::set_data_offset(unsigned addr) { r4811 = addr; r4812 = addr >> 8; r4813 = addr >> 16; }
void SPC7110::set_data_adjust(unsigned addr) { r4814 = addr; r4815 = addr >> 8; }
void SPC7110::data_port_read() {
unsigned offset = data_offset();
unsigned adjust = r4818 & 2 ? data_adjust() : 0;
if(r4818 & 8) adjust = (int16)adjust;
r4810 = datarom_read(offset + adjust);
}
void SPC7110::data_port_increment_4810() {
unsigned offset = data_offset();
unsigned stride = r4818 & 1 ? data_stride() : 1;
unsigned adjust = data_adjust();
if(r4818 & 4) stride = (int16)stride;
if(r4818 & 8) adjust = (int16)adjust;
if((r4818 & 16) == 0) set_data_offset(offset + stride);
if((r4818 & 16) != 0) set_data_adjust(adjust + stride);
data_port_read();
}
void SPC7110::data_port_increment_4814() {
if(r4818 >> 5 != 1) return;
unsigned offset = data_offset();
unsigned adjust = data_adjust();
if(r4818 & 8) adjust = (int16)adjust;
set_data_offset(offset + adjust);
data_port_read();
}
void SPC7110::data_port_increment_4815() {
if(r4818 >> 5 != 2) return;
unsigned offset = data_offset();
unsigned adjust = data_adjust();
if(r4818 & 8) adjust = (int16)adjust;
set_data_offset(offset + adjust);
data_port_read();
}
void SPC7110::data_port_increment_481a() {
if(r4818 >> 5 != 3) return;
unsigned offset = data_offset();
unsigned adjust = data_adjust();
if(r4818 & 8) adjust = (int16)adjust;
set_data_offset(offset + adjust);
data_port_read();
}
#endif