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65816.js
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leave stack pointer alteration with byte pushing or pulling to the mmu object

This commit is contained in:
Preston Skupinski 2011-05-11 17:31:50 -04:00
parent 4797ad0cd9
commit 7f6ce58d56
1 changed files with 51 additions and 43 deletions
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94
cpu.js
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@ -174,6 +174,14 @@ var MMU = {
cpu: {},
memory: { 0: {} },
pull_byte: function() {
return this.memory[this.cpu.r.dbr][++this.cpu.r.s];
},
push_byte: function(b) {
this.memory[this.cpu.r.dbr][this.cpu.r.s--] = b;
},
read_byte: function(location) {
return this.memory[this.cpu.r.dbr][location];
},
@ -299,9 +307,9 @@ var JSL = {
var location = cpu.r.pc - 1;
var low_byte = location & 0x00ff;
var high_byte = location >> 8;
cpu.mmu.store_byte(cpu.r.s--, cpu.r.pbr);
cpu.mmu.store_byte(cpu.r.s--, high_byte);
cpu.mmu.store_byte(cpu.r.s--, low_byte);
cpu.mmu.push_byte(cpu.r.pbr);
cpu.mmu.push_byte(high_byte);
cpu.mmu.push_byte(low_byte);
cpu.r.pbr = bytes[2];
cpu.r.pc = (bytes[1]<<8)|bytes[0];
}
@ -312,9 +320,9 @@ var RTL = {
return 1;
},
execute:function(cpu) {
var low_byte = cpu.mmu.read_byte(++cpu.r.s);
var high_byte = cpu.mmu.read_byte(++cpu.r.s);
cpu.r.pbr = cpu.mmu.read_byte(++cpu.r.s);
var low_byte = cpu.mmu.pull_byte();
var high_byte = cpu.mmu.pull_byte();
cpu.r.pbr = cpu.mmu.pull_byte();
cpu.r.pc = ((high_byte<<8)|low_byte) + 1;
}
};
@ -327,8 +335,8 @@ var JSR = {
var location = cpu.r.pc - 1;
var low_byte = location & 0x00ff;
var high_byte = location >> 8;
cpu.mmu.store_byte(cpu.r.s--, high_byte);
cpu.mmu.store_byte(cpu.r.s--, low_byte);
cpu.mmu.push_byte(high_byte);
cpu.mmu.push_byte(low_byte);
cpu.r.pc = (bytes[1]<<8)|bytes[0];
}
};
@ -338,8 +346,8 @@ var RTS = {
return 1;
},
execute:function(cpu) {
var low_byte = cpu.mmu.read_byte(++cpu.r.s);
var high_byte = cpu.mmu.read_byte(++cpu.r.s);
var low_byte = cpu.mmu.pull_byte();
var high_byte = cpu.mmu.pull_byte();
cpu.r.pc = ((high_byte<<8)|low_byte) + 1;
}
};
@ -352,8 +360,8 @@ var PER = {
var address = ((bytes[1]<<8)|bytes[0]) + cpu.r.pc;
var low_byte = address & 0x00ff;
var high_byte = address >> 8;
cpu.mmu.store_byte(cpu.r.s--, high_byte);
cpu.mmu.store_byte(cpu.r.s--, low_byte);
cpu.mmu.push_byte(high_byte);
cpu.mmu.push_byte(low_byte);
}
};
@ -362,7 +370,7 @@ var PHK = {
return 1;
},
execute:function(cpu) {
cpu.mmu.store_byte(cpu.r.s--, cpu.r.pbr);
cpu.mmu.push_byte(cpu.r.pbr);
}
};
@ -373,8 +381,8 @@ var PHD = {
execute:function(cpu) {
var low_byte = cpu.r.d & 0x00ff;
var high_byte = cpu.r.d >> 8;
cpu.mmu.store_byte(cpu.r.s--, high_byte);
cpu.mmu.store_byte(cpu.r.s--, low_byte);
cpu.mmu.push_byte(high_byte);
cpu.mmu.push_byte(low_byte);
}
};
@ -383,8 +391,8 @@ var PLD = {
return 1;
},
execute:function(cpu) {
var low_byte = cpu.mmu.read_byte(++cpu.r.s);
var high_byte = cpu.mmu.read_byte(++cpu.r.s);
var low_byte = cpu.mmu.pull_byte();
var high_byte = cpu.mmu.pull_byte();
cpu.r.d = (high_byte<<8)|low_byte;
cpu.p.n = cpu.r.d >> 15;
@ -402,7 +410,7 @@ var PHB = {
return 1;
},
execute:function(cpu) {
cpu.mmu.store_byte(cpu.r.s--, cpu.r.dbr);
cpu.mmu.push_byte(cpu.r.dbr);
}
};
@ -411,7 +419,7 @@ var PLB = {
return 1;
},
execute:function(cpu) {
cpu.r.dbr = cpu.mmu.read_byte(++cpu.r.s);
cpu.r.dbr = cpu.mmu.pull_byte();
cpu.p.n = cpu.r.dbr >> 7;
if(cpu.r.dbr===0) {
cpu.p.z = 1;
@ -426,8 +434,8 @@ var PEA = {
return 3;
},
execute:function(cpu, bytes) {
cpu.mmu.store_byte(cpu.r.s--, bytes[0]);
cpu.mmu.store_byte(cpu.r.s--, bytes[1]);
cpu.mmu.push_byte(bytes[0]);
cpu.mmu.push_byte(bytes[1]);
}
};
@ -439,8 +447,8 @@ var PEI = {
var location = bytes[0]+cpu.r.d;
var low_byte = cpu.mmu.read_byte(location);
var high_byte = cpu.mmu.read_byte(location+1);
cpu.mmu.store_byte(cpu.r.s--, high_byte);
cpu.mmu.store_byte(cpu.r.s--, low_byte);
cpu.mmu.push_byte(high_byte);
cpu.mmu.push_byte(low_byte);
}
};
@ -451,7 +459,7 @@ var PHP = {
execute:function(cpu) {
var p_byte = (cpu.p.n<<7)|(cpu.p.v<<6)|(cpu.p.m<<5)|(cpu.p.x<<4)|
(cpu.p.d<<3)|(cpu.p.i<<2)|(cpu.p.z<<1)|cpu.p.c;
cpu.mmu.store_byte(cpu.r.s--, p_byte);
cpu.mmu.push_byte(p_byte);
}
};
@ -460,7 +468,7 @@ var PLP = {
return 1;
},
execute:function(cpu) {
var p_byte = cpu.mmu.read_byte(++cpu.r.s);
var p_byte = cpu.mmu.pull_byte();
cpu.p.c = p_byte & 0x01;
cpu.p.z = (p_byte & 0x02) >> 1;
cpu.p.i = (p_byte & 0x04) >> 2;
@ -478,12 +486,12 @@ var PHX = {
},
execute:function(cpu) {
if(cpu.p.e|cpu.p.x) {
cpu.mmu.store_byte(cpu.r.s--, cpu.r.x);
cpu.mmu.push_byte(cpu.r.x);
} else {
var low_byte = cpu.r.x & 0x00ff;
var high_byte = cpu.r.x >> 8;
cpu.mmu.store_byte(cpu.r.s--, high_byte);
cpu.mmu.store_byte(cpu.r.s--, low_byte);
cpu.mmu.push_byte(high_byte);
cpu.mmu.push_byte(low_byte);
}
}
};
@ -494,11 +502,11 @@ var PLX = {
},
execute:function(cpu) {
if(cpu.p.e|cpu.p.x) {
cpu.r.x = cpu.mmu.read_byte(++cpu.r.s);
cpu.r.x = cpu.mmu.pull_byte();
cpu.p.n = cpu.r.x >> 7;
} else {
var low_byte = cpu.mmu.read_byte(++cpu.r.s);
var high_byte = cpu.mmu.read_byte(++cpu.r.s);
var low_byte = cpu.mmu.pull_byte();
var high_byte = cpu.mmu.pull_byte();
cpu.r.x = (high_byte<<8)|low_byte;
cpu.p.n = cpu.r.x >> 15;
}
@ -517,12 +525,12 @@ var PHY = {
},
execute:function(cpu) {
if(cpu.p.e|cpu.p.x) {
cpu.mmu.store_byte(cpu.r.s--, cpu.r.y);
cpu.mmu.push_byte(cpu.r.y);
} else {
var low_byte = cpu.r.y & 0x00ff;
var high_byte = cpu.r.y >> 8;
cpu.mmu.store_byte(cpu.r.s--, high_byte);
cpu.mmu.store_byte(cpu.r.s--, low_byte);
cpu.mmu.push_byte(high_byte);
cpu.mmu.push_byte(low_byte);
}
}
};
@ -533,11 +541,11 @@ var PLY = {
},
execute:function(cpu) {
if(cpu.p.e|cpu.p.x) {
cpu.r.y = cpu.mmu.read_byte(++cpu.r.s);
cpu.r.y = cpu.mmu.pull_byte();
cpu.p.n = cpu.r.y >> 7;
} else {
var low_byte = cpu.mmu.read_byte(++cpu.r.s);
var high_byte = cpu.mmu.read_byte(++cpu.r.s);
var low_byte = cpu.mmu.pull_byte();
var high_byte = cpu.mmu.pull_byte();
cpu.r.y = (high_byte<<8)|low_byte;
cpu.p.n = cpu.r.y >> 15;
}
@ -556,12 +564,12 @@ var PHA = {
},
execute:function(cpu) {
if(cpu.p.e|cpu.p.m) {
cpu.mmu.store_byte(cpu.r.s--, cpu.r.a);
cpu.mmu.push_byte(cpu.r.a);
} else {
var low_byte = cpu.r.a & 0x00ff;
var high_byte = cpu.r.a >> 8;
cpu.mmu.store_byte(cpu.r.s--, high_byte);
cpu.mmu.store_byte(cpu.r.s--, low_byte);
cpu.mmu.push_byte(high_byte);
cpu.mmu.push_byte(low_byte);
}
}
};
@ -572,11 +580,11 @@ var PLA = {
},
execute:function(cpu) {
if(cpu.p.e|cpu.p.m) {
cpu.r.a = cpu.mmu.read_byte(++cpu.r.s);
cpu.r.a = cpu.mmu.pull_byte();
cpu.p.n = cpu.r.a >> 7;
} else {
var low_byte = cpu.mmu.read_byte(++cpu.r.s);
var high_byte = cpu.mmu.read_byte(++cpu.r.s);
var low_byte = cpu.mmu.pull_byte();
var high_byte = cpu.mmu.pull_byte();
cpu.r.a = (high_byte<<8)|low_byte;
cpu.p.n = cpu.r.a >> 15;
}