The-Homebrew-Cloud/snes9xgx
2
0
Fork 0
mirror of https://github.com/dborth/snes9xgx.git synced 2024-11-01 16:35:16 +01:00
Code Issues Packages Projects Releases Wiki Activity
f69cd5baee
snes9xgx/source/snes9x/spc7110emu.cpp
Daryl Borth 845e69d889 revert remainder of snes9x code back
2018-08-20 09:11:01 -06:00

648 lines
17 KiB
C++
Raw Blame History

/*****
* SPC7110 emulator - version 0.03 (2008-08-10)
* Copyright (c) 2008, byuu and neviksti
*
* Permission to use, copy, modify, and/or distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* The software is provided "as is" and the author disclaims all warranties
* with regard to this software including all implied warranties of
* merchantibility and fitness, in no event shall the author be liable for
* any special, direct, indirect, or consequential damages or any damages
* whatsoever resulting from loss of use, data or profits, whether in an
* action of contract, negligence or other tortious action, arising out of
* or in connection with the use or performance of this software.
*****/
#ifdef _SPC7110EMU_CPP_
#include "spc7110dec.cpp"
const unsigned SPC7110::months[12] = { 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 };
void SPC7110::power() {
reset();
}
void SPC7110::reset() {
r4801 = 0x00;
r4802 = 0x00;
r4803 = 0x00;
r4804 = 0x00;
r4805 = 0x00;
r4806 = 0x00;
r4807 = 0x00;
r4808 = 0x00;
r4809 = 0x00;
r480a = 0x00;
r480b = 0x00;
r480c = 0x00;
decomp.reset();
r4811 = 0x00;
r4812 = 0x00;
r4813 = 0x00;
r4814 = 0x00;
r4815 = 0x00;
r4816 = 0x00;
r4817 = 0x00;
r4818 = 0x00;
r481x = 0x00;
r4814_latch = false;
r4815_latch = false;
r4820 = 0x00;
r4821 = 0x00;
r4822 = 0x00;
r4823 = 0x00;
r4824 = 0x00;
r4825 = 0x00;
r4826 = 0x00;
r4827 = 0x00;
r4828 = 0x00;
r4829 = 0x00;
r482a = 0x00;
r482b = 0x00;
r482c = 0x00;
r482d = 0x00;
r482e = 0x00;
r482f = 0x00;
r4830 = 0x00;
mmio_write(0x4831, 0);
mmio_write(0x4832, 1);
mmio_write(0x4833, 2);
r4834 = 0x00;
r4840 = 0x00;
r4841 = 0x00;
r4842 = 0x00;
if(cartridge_info_spc7110rtc) {
rtc_state = RTCS_Inactive;
rtc_mode = RTCM_Linear;
rtc_index = 0;
}
}
unsigned SPC7110::datarom_addr(unsigned addr) {
unsigned size = memory_cartrom_size() - 0x100000;
while(addr >= size) addr -= size;
return addr + 0x100000;
}
unsigned SPC7110::data_pointer() { return r4811 + (r4812 << 8) + (r4813 << 16); }
unsigned SPC7110::data_adjust() { return r4814 + (r4815 << 8); }
unsigned SPC7110::data_increment() { return r4816 + (r4817 << 8); }
void SPC7110::set_data_pointer(unsigned addr) { r4811 = addr; r4812 = addr >> 8; r4813 = addr >> 16; }
void SPC7110::set_data_adjust(unsigned addr) { r4814 = addr; r4815 = addr >> 8; }
void SPC7110::update_time(int offset) {
time_t rtc_time
= (memory_cartrtc_read(16) << 0)
| (memory_cartrtc_read(17) << 8)
| (memory_cartrtc_read(18) << 16)
| (memory_cartrtc_read(19) << 24);
time_t current_time = time(0) - offset;
//sizeof(time_t) is platform-dependent; though memory::cartrtc needs to be platform-agnostic.
//yet platforms with 32-bit signed time_t will overflow every ~68 years. handle this by
//accounting for overflow at the cost of 1-bit precision (to catch underflow). this will allow
//memory::cartrtc timestamp to remain valid for up to ~34 years from the last update, even if
//time_t overflows. calculation should be valid regardless of number representation, time_t size,
//or whether time_t is signed or unsigned.
time_t diff
= (current_time >= rtc_time)
? (current_time - rtc_time)
: (std::numeric_limits<time_t>::max() - rtc_time + current_time + 1); //compensate for overflow
if(diff > std::numeric_limits<time_t>::max() / 2) diff = 0; //compensate for underflow
bool update = true;
if(memory_cartrtc_read(13) & 1) update = false; //do not update if CR0 timer disable flag is set
if(memory_cartrtc_read(15) & 3) update = false; //do not update if CR2 timer disable flags are set
if(diff > 0 && update == true) {
unsigned second = memory_cartrtc_read( 0) + memory_cartrtc_read( 1) * 10;
unsigned minute = memory_cartrtc_read( 2) + memory_cartrtc_read( 3) * 10;
unsigned hour = memory_cartrtc_read( 4) + memory_cartrtc_read( 5) * 10;
unsigned day = memory_cartrtc_read( 6) + memory_cartrtc_read( 7) * 10;
unsigned month = memory_cartrtc_read( 8) + memory_cartrtc_read( 9) * 10;
unsigned year = memory_cartrtc_read(10) + memory_cartrtc_read(11) * 10;
unsigned weekday = memory_cartrtc_read(12);
day--;
month--;
year += (year >= 90) ? 1900 : 2000; //range = 1990-2089
second += diff;
while(second >= 60) {
second -= 60;
minute++;
if(minute < 60) continue;
minute = 0;
hour++;
if(hour < 24) continue;
hour = 0;
day++;
weekday = (weekday + 1) % 7;
unsigned days = months[month % 12];
if(days == 28) {
bool leapyear = false;
if((year % 4) == 0) {
leapyear = true;
if((year % 100) == 0 && (year % 400) != 0) leapyear = false;
}
if(leapyear) days++;
}
if(day < days) continue;
day = 0;
month++;
if(month < 12) continue;
month = 0;
year++;
}
day++;
month++;
year %= 100;
memory_cartrtc_write( 0, second % 10);
memory_cartrtc_write( 1, second / 10);
memory_cartrtc_write( 2, minute % 10);
memory_cartrtc_write( 3, minute / 10);
memory_cartrtc_write( 4, hour % 10);
memory_cartrtc_write( 5, hour / 10);
memory_cartrtc_write( 6, day % 10);
memory_cartrtc_write( 7, day / 10);
memory_cartrtc_write( 8, month % 10);
memory_cartrtc_write( 9, month / 10);
memory_cartrtc_write(10, year % 10);
memory_cartrtc_write(11, (year / 10) % 10);
memory_cartrtc_write(12, weekday % 7);
}
memory_cartrtc_write(16, current_time >> 0);
memory_cartrtc_write(17, current_time >> 8);
memory_cartrtc_write(18, current_time >> 16);
memory_cartrtc_write(19, current_time >> 24);
}
uint8 SPC7110::mmio_read(unsigned addr) {
addr &= 0xffff;
switch(addr) {
//==================
//decompression unit
//==================
case 0x4800: {
uint16 counter = (r4809 + (r480a << 8));
counter--;
r4809 = counter;
r480a = counter >> 8;
return decomp.read();
}
case 0x4801: return r4801;
case 0x4802: return r4802;
case 0x4803: return r4803;
case 0x4804: return r4804;
case 0x4805: return r4805;
case 0x4806: return r4806;
case 0x4807: return r4807;
case 0x4808: return r4808;
case 0x4809: return r4809;
case 0x480a: return r480a;
case 0x480b: return r480b;
case 0x480c: {
uint8 status = r480c;
r480c &= 0x7f;
return status;
}
//==============
//data port unit
//==============
case 0x4810: {
if(r481x != 0x07) return 0x00;
unsigned addr = data_pointer();
unsigned adjust = data_adjust();
if(r4818 & 8) adjust = (int16)adjust; //16-bit sign extend
unsigned adjustaddr = addr;
if(r4818 & 2) {
adjustaddr += adjust;
set_data_adjust(adjust + 1);
}
uint8 data = memory_cartrom_read(datarom_addr(adjustaddr));
if(!(r4818 & 2)) {
unsigned increment = (r4818 & 1) ? data_increment() : 1;
if(r4818 & 4) increment = (int16)increment; //16-bit sign extend
if((r4818 & 16) == 0) {
set_data_pointer(addr + increment);
} else {
set_data_adjust(adjust + increment);
}
}
return data;
}
case 0x4811: return r4811;
case 0x4812: return r4812;
case 0x4813: return r4813;
case 0x4814: return r4814;
case 0x4815: return r4815;
case 0x4816: return r4816;
case 0x4817: return r4817;
case 0x4818: return r4818;
case 0x481a: {
if(r481x != 0x07) return 0x00;
unsigned addr = data_pointer();
unsigned adjust = data_adjust();
if(r4818 & 8) adjust = (int16)adjust; //16-bit sign extend
uint8 data = memory_cartrom_read(datarom_addr(addr + adjust));
if((r4818 & 0x60) == 0x60) {
if((r4818 & 16) == 0) {
set_data_pointer(addr + adjust);
} else {
set_data_adjust(adjust + adjust);
}
}
return data;
}
//=========
//math unit
//=========
case 0x4820: return r4820;
case 0x4821: return r4821;
case 0x4822: return r4822;
case 0x4823: return r4823;
case 0x4824: return r4824;
case 0x4825: return r4825;
case 0x4826: return r4826;
case 0x4827: return r4827;
case 0x4828: return r4828;
case 0x4829: return r4829;
case 0x482a: return r482a;
case 0x482b: return r482b;
case 0x482c: return r482c;
case 0x482d: return r482d;
case 0x482e: return r482e;
case 0x482f: {
uint8 status = r482f;
r482f &= 0x7f;
return status;
}
//===================
//memory mapping unit
//===================
case 0x4830: return r4830;
case 0x4831: return r4831;
case 0x4832: return r4832;
case 0x4833: return r4833;
case 0x4834: return r4834;
//====================
//real-time clock unit
//====================
case 0x4840: return r4840;
case 0x4841: {
if(rtc_state == RTCS_Inactive || rtc_state == RTCS_ModeSelect) return 0x00;
r4842 = 0x80;
uint8 data = memory_cartrtc_read(rtc_index);
rtc_index = (rtc_index + 1) & 15;
return data;
}
case 0x4842: {
uint8 status = r4842;
r4842 &= 0x7f;
return status;
}
}
return cpu_regs_mdr;
}
void SPC7110::mmio_write(unsigned addr, uint8 data) {
addr &= 0xffff;
switch(addr) {
//==================
//decompression unit
//==================
case 0x4801: r4801 = data; break;
case 0x4802: r4802 = data; break;
case 0x4803: r4803 = data; break;
case 0x4804: r4804 = data; break;
case 0x4805: r4805 = data; break;
case 0x4806: {
r4806 = data;
unsigned table = (r4801 + (r4802 << 8) + (r4803 << 16));
unsigned index = (r4804 << 2);
//unsigned length = (r4809 + (r480a << 8));
unsigned addr = datarom_addr(table + index);
unsigned mode = (memory_cartrom_read(addr + 0));
unsigned offset = (memory_cartrom_read(addr + 1) << 16)
+ (memory_cartrom_read(addr + 2) << 8)
+ (memory_cartrom_read(addr + 3) << 0);
decomp.init(mode, offset, (r4805 + (r4806 << 8)) << mode);
r480c = 0x80;
} break;
case 0x4807: r4807 = data; break;
case 0x4808: r4808 = data; break;
case 0x4809: r4809 = data; break;
case 0x480a: r480a = data; break;
case 0x480b: r480b = data; break;
//==============
//data port unit
//==============
case 0x4811: r4811 = data; r481x |= 0x01; break;
case 0x4812: r4812 = data; r481x |= 0x02; break;
case 0x4813: r4813 = data; r481x |= 0x04; break;
case 0x4814: {
r4814 = data;
r4814_latch = true;
if(!r4815_latch) break;
if(!(r4818 & 2)) break;
if(r4818 & 0x10) break;
if((r4818 & 0x60) == 0x20) {
unsigned increment = data_adjust() & 0xff;
if(r4818 & 8) increment = (int8)increment; //8-bit sign extend
set_data_pointer(data_pointer() + increment);
} else if((r4818 & 0x60) == 0x40) {
unsigned increment = data_adjust();
if(r4818 & 8) increment = (int16)increment; //16-bit sign extend
set_data_pointer(data_pointer() + increment);
}
} break;
case 0x4815: {
r4815 = data;
r4815_latch = true;
if(!r4814_latch) break;
if(!(r4818 & 2)) break;
if(r4818 & 0x10) break;
if((r4818 & 0x60) == 0x20) {
unsigned increment = data_adjust() & 0xff;
if(r4818 & 8) increment = (int8)increment; //8-bit sign extend
set_data_pointer(data_pointer() + increment);
} else if((r4818 & 0x60) == 0x40) {
unsigned increment = data_adjust();
if(r4818 & 8) increment = (int16)increment; //16-bit sign extend
set_data_pointer(data_pointer() + increment);
}
} break;
case 0x4816: r4816 = data; break;
case 0x4817: r4817 = data; break;
case 0x4818: {
if(r481x != 0x07) break;
r4818 = data;
r4814_latch = r4815_latch = false;
} break;
//=========
//math unit
//=========
case 0x4820: r4820 = data; break;
case 0x4821: r4821 = data; break;
case 0x4822: r4822 = data; break;
case 0x4823: r4823 = data; break;
case 0x4824: r4824 = data; break;
case 0x4825: {
r4825 = data;
if(r482e & 1) {
//signed 16-bit x 16-bit multiplication
int16 r0 = (int16)(r4824 + (r4825 << 8));
int16 r1 = (int16)(r4820 + (r4821 << 8));
signed result = r0 * r1;
r4828 = result;
r4829 = result >> 8;
r482a = result >> 16;
r482b = result >> 24;
} else {
//unsigned 16-bit x 16-bit multiplication
uint16 r0 = (uint16)(r4824 + (r4825 << 8));
uint16 r1 = (uint16)(r4820 + (r4821 << 8));
unsigned result = r0 * r1;
r4828 = result;
r4829 = result >> 8;
r482a = result >> 16;
r482b = result >> 24;
}
r482f = 0x80;
} break;
case 0x4826: r4826 = data; break;
case 0x4827: {
r4827 = data;
if(r482e & 1) {
//signed 32-bit x 16-bit division
int32 dividend = (int32)(r4820 + (r4821 << 8) + (r4822 << 16) + (r4823 << 24));
int16 divisor = (int16)(r4826 + (r4827 << 8));
int32 quotient;
int16 remainder;
if(divisor) {
quotient = (int32)(dividend / divisor);
remainder = (int32)(dividend % divisor);
} else {
//illegal division by zero
quotient = 0;
remainder = dividend & 0xffff;
}
r4828 = quotient;
r4829 = quotient >> 8;
r482a = quotient >> 16;
r482b = quotient >> 24;
r482c = remainder;
r482d = remainder >> 8;
} else {
//unsigned 32-bit x 16-bit division
uint32 dividend = (uint32)(r4820 + (r4821 << 8) + (r4822 << 16) + (r4823 << 24));
uint16 divisor = (uint16)(r4826 + (r4827 << 8));
uint32 quotient;
uint16 remainder;
if(divisor) {
quotient = (uint32)(dividend / divisor);
remainder = (uint16)(dividend % divisor);
} else {
//illegal division by zero
quotient = 0;
remainder = dividend & 0xffff;
}
r4828 = quotient;
r4829 = quotient >> 8;
r482a = quotient >> 16;
r482b = quotient >> 24;
r482c = remainder;
r482d = remainder >> 8;
}
r482f = 0x80;
} break;
case 0x482e: {
//reset math unit
r4820 = r4821 = r4822 = r4823 = 0;
r4824 = r4825 = r4826 = r4827 = 0;
r4828 = r4829 = r482a = r482b = 0;
r482c = r482d = 0;
r482e = data;
} break;
//===================
//memory mapping unit
//===================
case 0x4830: r4830 = data; break;
case 0x4831: {
r4831 = data;
dx_offset = datarom_addr((data & 7) * 0x100000);
} break;
case 0x4832: {
r4832 = data;
ex_offset = datarom_addr((data & 7) * 0x100000);
} break;
case 0x4833: {
r4833 = data;
fx_offset = datarom_addr((data & 7) * 0x100000);
} break;
case 0x4834: r4834 = data; break;
//====================
//real-time clock unit
//====================
case 0x4840: {
r4840 = data;
if(!(r4840 & 1)) {
//disable RTC
rtc_state = RTCS_Inactive;
update_time();
} else {
//enable RTC
r4842 = 0x80;
rtc_state = RTCS_ModeSelect;
}
} break;
case 0x4841: {
r4841 = data;
switch(rtc_state) {
case RTCS_ModeSelect: {
if(data == RTCM_Linear || data == RTCM_Indexed) {
r4842 = 0x80;
rtc_state = RTCS_IndexSelect;
rtc_mode = (RTC_Mode)data;
rtc_index = 0;
}
} break;
case RTCS_IndexSelect: {
r4842 = 0x80;
rtc_index = data & 15;
if(rtc_mode == RTCM_Linear) rtc_state = RTCS_Write;
} break;
case RTCS_Write: {
r4842 = 0x80;
//control register 0
if(rtc_index == 13) {
//increment second counter
if(data & 2) update_time(+1);
//round minute counter
if(data & 8) {
update_time();
unsigned second = memory_cartrtc_read( 0) + memory_cartrtc_read( 1) * 10;
//clear seconds
memory_cartrtc_write(0, 0);
memory_cartrtc_write(1, 0);
if(second >= 30) update_time(+60);
}
}
//control register 2
if(rtc_index == 15) {
//disable timer and clear second counter
if((data & 1) && !(memory_cartrtc_read(15) & 1)) {
update_time();
//clear seconds
memory_cartrtc_write(0, 0);
memory_cartrtc_write(1, 0);
}
//disable timer
if((data & 2) && !(memory_cartrtc_read(15) & 2)) {
update_time();
}
}
memory_cartrtc_write(rtc_index, data & 15);
rtc_index = (rtc_index + 1) & 15;
} break;
case RTCS_Inactive: {
} break;
} //switch(rtc_state)
} break;
}
}
SPC7110::SPC7110() {
}
#endif
Reference in New Issue View Git Blame Copy Permalink