#ifdef SMP_CPP alwaysinline uint8 SMP::ram_read(uint16 addr) { if(addr >= 0xffc0 && status.iplrom_enable) return iplrom[addr & 0x3f]; if(status.ram_disable) return 0x5a; //0xff on mini-SNES return apuram[addr]; } alwaysinline void SMP::ram_write(uint16 addr, uint8 data) { //writes to $ffc0-$ffff always go to apuram, even if the iplrom is enabled if(status.ram_writable && !status.ram_disable) apuram[addr] = data; } uint8 SMP::port_read(uint2 port) const { return apuram[0xf4 + port]; } void SMP::port_write(uint2 port, uint8 data) { apuram[0xf4 + port] = data; } uint8 SMP::op_busread(uint16 addr) { unsigned result; switch(addr) { case 0xf0: //TEST -- write-only register return 0x00; case 0xf1: //CONTROL -- write-only register return 0x00; case 0xf2: //DSPADDR return status.dsp_addr; case 0xf3: //DSPDATA //0x80-0xff are read-only mirrors of 0x00-0x7f return dsp.read(status.dsp_addr & 0x7f); case 0xf4: //CPUIO0 case 0xf5: //CPUIO1 case 0xf6: //CPUIO2 case 0xf7: //CPUIO3 synchronize_cpu(); return cpu.port_read(addr); case 0xf8: //RAM0 return status.ram00f8; case 0xf9: //RAM1 return status.ram00f9; case 0xfa: //T0TARGET case 0xfb: //T1TARGET case 0xfc: //T2TARGET -- write-only registers return 0x00; case 0xfd: //T0OUT -- 4-bit counter value result = timer0.stage3_ticks; timer0.stage3_ticks = 0; return result; case 0xfe: //T1OUT -- 4-bit counter value result = timer1.stage3_ticks; timer1.stage3_ticks = 0; return result; case 0xff: //T2OUT -- 4-bit counter value result = timer2.stage3_ticks; timer2.stage3_ticks = 0; return result; } return ram_read(addr); } void SMP::op_buswrite(uint16 addr, uint8 data) { switch(addr) { case 0xf0: //TEST if(regs.p.p) break; //writes only valid when P flag is clear status.clock_speed = (data >> 6) & 3; status.timer_speed = (data >> 4) & 3; status.timers_enable = data & 0x08; status.ram_disable = data & 0x04; status.ram_writable = data & 0x02; status.timers_disable = data & 0x01; status.timer_step = (1 << status.clock_speed) + (2 << status.timer_speed); timer0.synchronize_stage1(); timer1.synchronize_stage1(); timer2.synchronize_stage1(); break; case 0xf1: //CONTROL status.iplrom_enable = data & 0x80; if(data & 0x30) { //one-time clearing of APU port read registers, //emulated by simulating CPU writes of 0x00 synchronize_cpu(); if(data & 0x20) { cpu.port_write(2, 0x00); cpu.port_write(3, 0x00); } if(data & 0x10) { cpu.port_write(0, 0x00); cpu.port_write(1, 0x00); } } //0->1 transistion resets timers if(timer2.enable == false && (data & 0x04)) { timer2.stage2_ticks = 0; timer2.stage3_ticks = 0; } timer2.enable = data & 0x04; if(timer1.enable == false && (data & 0x02)) { timer1.stage2_ticks = 0; timer1.stage3_ticks = 0; } timer1.enable = data & 0x02; if(timer0.enable == false && (data & 0x01)) { timer0.stage2_ticks = 0; timer0.stage3_ticks = 0; } timer0.enable = data & 0x01; break; case 0xf2: //DSPADDR status.dsp_addr = data; break; case 0xf3: //DSPDATA if(status.dsp_addr & 0x80) break; //0x80-0xff are read-only mirrors of 0x00-0x7f dsp.write(status.dsp_addr & 0x7f, data); break; case 0xf4: //CPUIO0 case 0xf5: //CPUIO1 case 0xf6: //CPUIO2 case 0xf7: //CPUIO3 synchronize_cpu(); port_write(addr, data); break; case 0xf8: //RAM0 status.ram00f8 = data; break; case 0xf9: //RAM1 status.ram00f9 = data; break; case 0xfa: //T0TARGET timer0.target = data; break; case 0xfb: //T1TARGET timer1.target = data; break; case 0xfc: //T2TARGET timer2.target = data; break; case 0xfd: //T0OUT case 0xfe: //T1OUT case 0xff: //T2OUT -- read-only registers break; } ram_write(addr, data); //all writes, even to MMIO registers, appear on bus } void SMP::op_io() { add_clocks(24); cycle_edge(); } uint8 SMP::op_read(uint16 addr) { add_clocks(12); uint8 data = op_busread(addr); add_clocks(12); cycle_edge(); debugger.op_read(addr, data); return data; } void SMP::op_write(uint16 addr, uint8 data) { add_clocks(24); op_buswrite(addr, data); cycle_edge(); debugger.op_write(addr, data); } uint8 SMP::disassembler_read(uint16 addr) { if((addr & 0xfff0) == 0x00f0) return 0x00; if((addr & 0xffc0) == 0xffc0 && status.iplrom_enable) return iplrom[addr & 0x3f]; return apuram[addr]; } #endif