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games/snes: added decimal mode and wai

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This commit is contained in:
aiju 2014-03-14 15:06:21 +01:00
parent ff677a1cb4
commit 289fb207c9
1 changed files with 67 additions and 20 deletions
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87
sys/src/games/snes/cpu.c
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@ -4,7 +4,7 @@
#include "dat.h"
#include "fns.h"
u8int rP, emu, irq, nmi, dma;
u8int rP, emu, irq, nmi, dma, wai;
u16int rA, rX, rY, rS, rD, pc;
u32int rDB, rPB, curpc, hdma;
static u8int m8, x8;
@ -329,29 +329,51 @@ adc(u16int a)
{
int r;
if((rP & FLAGD) != 0)
print("decimal mode\n");
if(m8){
r = (rA & 0xff) + a + (rP & FLAGC);
if((rP & FLAGD) != 0){
r = (rA & 0xf) + (a & 0xf) + (rP & FLAGC);
if(r > 0x09)
r += 0x06;
if(r > 0x1f)
r -= 0x10;
r += (rA & 0xf0) + (a & 0xf0);
}else
r = (rA & 0xff) + a + (rP & FLAGC);
rP &= ~(FLAGC | FLAGN | FLAGV | FLAGZ);
if((~(rA ^ a) & (rA ^ r)) & 0x80)
rP |= FLAGV;
if((rP & FLAGD) != 0 && r > 0x9f)
r += 0x60;
if(r > 0xFF)
rP |= FLAGC;
rP |= r & 0x80;
if((~(rA ^ a) & (rA ^ r)) & 0x80)
rP |= FLAGV;
r &= 0xFF;
if(r == 0)
rP |= FLAGZ;
rA = rA & 0xFF00 | r;
}else{
r = rA + a + (rP & FLAGC);
if((rP & FLAGD) != 0){
r = (rA & 0x000f) + (a & 0x000f) + (rP & FLAGC);
if(r > 0x0009) r += 0x0006;
if(r > 0x001f) r -= 0x0010;
r += (rA & 0x00f0) + (a & 0x00f0);
if(r > 0x0090) r += 0x0060;
if(r > 0x01f0) r -= 0x0100;
r += (rA & 0x0f00) + (a & 0x0f00);
if(r > 0x0900) r += 0x0600;
if(r > 0x1f00) r -= 0x1000;
r += (rA & 0xf000) + (a & 0xf000);
}else
r = rA + a + (rP & FLAGC);
rP &= ~(FLAGC | FLAGN | FLAGV | FLAGZ);
if((~(rA ^ a) & (rA ^ r)) & 0x8000)
rP |= FLAGV;
if((rP & FLAGD) != 0 && r > 0x9fff)
r += 0x6000;
if(r > 0xFFFF)
rP |= FLAGC;
if((r & 0x8000) != 0)
rP |= FLAGN;
if((~(rA ^ a) & (rA ^ r)) & 0x8000)
rP |= FLAGV;
rA = r;
if(rA == 0)
rP |= FLAGZ;
@ -478,34 +500,51 @@ sbc(u16int a)
{
int r;
if((rP & FLAGD) != 0)
print("decimal mode\n");
if(m8){
r = (rA & 0xff) + (a ^ 0xff) + (rP & FLAGC);
a ^= 0xff;
if((rP & FLAGD) != 0){
r = (rA & 0xf) + (a & 0xf) + (rP & FLAGC);
if(r < 0x10) r -= 0x06;
r += (rA & 0xf0) + (a & 0xf0);
}else
r = (rA & 0xff) + a + (rP & FLAGC);
rP &= ~(FLAGC | FLAGN | FLAGV | FLAGZ);
if(r > 0xFF)
rP |= FLAGC;
rP |= r & 0x80;
if(((rA ^ a) & (rA ^ r)) & 0x80)
if((~(rA ^ a) & (rA ^ r)) & 0x80)
rP |= FLAGV;
if(r > 0xff)
rP |= FLAGC;
else if((rP & FLAGD) != 0)
r -= 0x60;
rP |= r & 0x80;
r &= 0xFF;
if(r == 0)
rP |= FLAGZ;
rA = rA & 0xFF00 | r;
}else{
r = rA + (a ^ 0xffff) + (rP & FLAGC);
a ^= 0xffff;
if((rP & FLAGD) != 0){
r = (rA & 0x000f) + (a & 0x000f) + (rP & FLAGC);
if(r < 0x0010) r -= 0x0006;
r += (rA & 0x00f0) + (a & 0x00f0);
if(r < 0x0100) r -= 0x0060;
r += (rA & 0x0f00) + (a & 0x0f00);
if(r < 0x1000) r -= 0x0600;
r += (rA & 0xf000) + (a & 0xf000);
}else
r = rA + a + (rP & FLAGC);
rP &= ~(FLAGC | FLAGN | FLAGV | FLAGZ);
if((~(rA ^ a) & (rA ^ r)) & 0x8000)
rP |= FLAGV;
if(r > 0xFFFF)
rP |= FLAGC;
else if((rP & FLAGD) != 0)
r -= 0x6000;
if((r & 0x8000) != 0)
rP |= FLAGN;
if(((rA ^ a) & (rA ^ r)) & 0x8000)
rP |= FLAGV;
rA = r;
if(rA == 0)
rP |= FLAGZ;
}
}
static void
@ -565,6 +604,7 @@ interrupt(int src)
rPB = 0;
if(emu)
rDB = 0;
wai = 0;
}
void
@ -605,6 +645,11 @@ cpustep(void)
return 8 - emu;
}
curpc = pc|rPB;
if(wai)
if(irq)
wai = 0;
else
return 1;
m8 = (rP & FLAGM) != 0;
x8 = (rP & FLAGX) != 0;
op = fetch8();
@ -888,6 +933,7 @@ cpustep(void)
rX &= 0xff;
nzx(rX);
return 2;
case 0xCB: wai = 1; return 1;
case 0xCC: cmp(rY, memx816(abso(0, 0)), x8); return 4+cyc;
case 0xCD: cmp(rA, mem816(abso(0, 0), 0), m8); return 4+cyc;
case 0xCE: dec(abso(0, 0)); return 6+cyc;
@ -903,6 +949,7 @@ cpustep(void)
case 0xD8: rP &= ~FLAGD; return 2;
case 0xD9: cmp(rA, mem816(abso(0, 2), 0), m8); return 4+cyc;
case 0xDA: push816(rX, x8); return 3+cyc;
case 0xDB: print("STP\n"); return 2;
case 0xDC: a = fetch16(); pc = memread(a) | memread((u16int)(a+1))<<8; rPB = memread((u16int)(a+2)) << 16; return 6;
case 0xDD: cmp(rA, mem816(abso(0, 1), 0), m8); return 4+cyc;
case 0xDE: dec(abso(0, 1)); return 7+cyc;