6502
/
65816.js
mirror of https://github.com/pskupinski/65816.js.git
1
0
Fork 0
Code Issues Projects Releases Wiki Activity

added LSR and all of the addressing modes for and rewrote the way in which I get the high byte from 16-bit data

This commit is contained in:
Preston Skupinski 2011-05-08 14:03:59 -04:00
parent c941641d6a
commit e8e96e0164
1 changed files with 139 additions and 29 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

168
cpu.js
View File

@ -110,7 +110,10 @@ function CPU_65816() {
0x52 : EOR_direct_page_indirect,
0x5d : EOR_absolute_indexed_x,
0x59 : EOR_absolute_indexed_y,
0x55 : EOR_direct_page_indexed_x };
0x55 : EOR_direct_page_indexed_x,
0x4a : LSR_accumulator, 0x4e : LSR_absolute,
0x46 : LSR_direct_page, 0x5e : LSR_absolute_indexed_x,
0x56 : LSR_direct_page_indexed_x };
/**
* Take a raw hex string representing the program and execute it.
@ -189,6 +192,113 @@ var MMU = {
}
};
var LSR_accumulator = {
bytes_required:function(cpu) {
return 1;
},
execute:function(cpu) {
if(cpu.p.m) {
cpu.p.c = cpu.r.a & 0x0001;
} else {
cpu.p.c = cpu.r.a & 0x01;
}
cpu.r.a = cpu.r.a >> 1;
cpu.p.n = 0;
if(cpu.r.a===0) {
cpu.p.z = 1;
} else {
cpu.p.z = 0;
}
}
};
var LSR_absolute = {
bytes_required:function() {
return 3;
},
execute:function(cpu, bytes) {
var location = (bytes[1]<<8)|bytes[0];
var shiftee;
if(cpu.p.m) {
shiftee = cpu.mmu.ready_byte(location);
cpu.p.c = shiftee & 0x0001;
shiftee = shiftee >> 1;
cpu.mmu.store_byte(location, shiftee);
} else {
var low_byte = cpu.mmu.read_byte(location);
var high_byte = cpu.mmu.read_byte(location+1);
shiftee = (high_byte<<8)|low_byte;
cpu.p.c = cpu.r.a & 0x01;
shiftee = shiftee >> 1;
low_byte = shiftee & 0x00ff;
high_byte = shiftee >> 8;
cpu.mmu.store_byte(location, low_byte);
cpu.mmu.store_byte(location+1, high_byte);
}
cpu.p.n = 0;
if(shiftee===0) {
cpu.p.z = 1;
} else {
cpu.p.z = 0;
}
}
};
var LSR_direct_page = {
bytes_required:function() {
return 2;
},
execute:function(cpu, bytes) {
var shiftee;
if(cpu.p.m) {
shiftee = cpu.mmu.ready_byte(bytes[0]);
cpu.p.c = shiftee & 0x0001;
shiftee = shiftee >> 1;
cpu.mmu.store_byte(bytes[0], shiftee);
} else {
var low_byte = cpu.mmu.read_byte(bytes[0]);
var high_byte = cpu.mmu.read_byte(bytes[0]+1);
shiftee = (high_byte<<8)|low_byte;
cpu.p.c = cpu.r.a & 0x01;
shiftee = shiftee >> 1;
low_byte = shiftee & 0x00ff;
high_byte = shiftee >> 8;
cpu.mmu.store_byte(bytes[0], low_byte);
cpu.mmu.store_byte(bytes[0]+1, high_byte);
}
cpu.p.n = 0;
if(shiftee===0) {
cpu.p.z = 1;
} else {
cpu.p.z = 0;
}
}
};
var LSR_absolute_indexed_x = {
bytes_required:function() {
return 3;
},
execute:function(cpu, bytes) {
var location = ((bytes[1]<<8)|bytes[0])+cpu.r.x;
var location_high_byte = location >> 8;
var location_low_byte = location & 0x00ff;
LSR_absolute.execute(cpu, [location_low_byte, location_high_byte]);
}
};
var LSR_direct_page_indexed_x = {
bytes_required:function() {
return 2;
},
execute:function(cpu, bytes) {
LSR_direct_page.execute(cpu, [bytes[0]+cpu.r.x]);
}
};
var EOR_const = {
bytes_required:function(cpu) {
if(cpu.p.m) {
@ -271,7 +381,7 @@ var EOR_absolute_indexed_x = {
},
execute:function(cpu, bytes) {
var location = ((bytes[1]<<8)|bytes[0])+cpu.r.x;
var location_high_byte = (location & 0xff00)>>8;
var location_high_byte = location >> 8;
var location_low_byte = location & 0x00ff;
EOR_absolute.execute(cpu, [location_low_byte, location_high_byte]);
}
@ -283,7 +393,7 @@ var EOR_absolute_indexed_y = {
},
execute:function(cpu, bytes) {
var location = ((bytes[1]<<8)|bytes[0])+cpu.r.y;
var location_high_byte = (location & 0xff00)>>8;
var location_high_byte = location >> 8;
var location_low_byte = location & 0x00ff;
EOR_absolute.execute(cpu, [location_low_byte, location_high_byte]);
}
@ -380,7 +490,7 @@ var ORA_absolute_indexed_x = {
},
execute:function(cpu, bytes) {
var location = ((bytes[1]<<8)|bytes[0])+cpu.r.x;
var location_high_byte = (location & 0xff00)>>8;
var location_high_byte = location >> 8;
var location_low_byte = location & 0x00ff;
ORA_absolute.execute(cpu, [location_low_byte, location_high_byte]);
}
@ -392,7 +502,7 @@ var ORA_absolute_indexed_y = {
},
execute:function(cpu, bytes) {
var location = ((bytes[1]<<8)|bytes[0])+cpu.r.y;
var location_high_byte = (location & 0xff00)>>8;
var location_high_byte = location >> 8;
var location_low_byte = location & 0x00ff;
ORA_absolute.execute(cpu, [location_low_byte, location_high_byte]);
}
@ -489,7 +599,7 @@ var AND_absolute_indexed_x = {
},
execute:function(cpu, bytes) {
var location = ((bytes[1]<<8)|bytes[0])+cpu.r.x;
var location_high_byte = (location & 0xff00)>>8;
var location_high_byte = location >> 8;
var location_low_byte = location & 0x00ff;
AND_absolute.execute(cpu, [location_low_byte, location_high_byte]);
}
@ -501,7 +611,7 @@ var AND_absolute_indexed_y = {
},
execute:function(cpu, bytes) {
var location = ((bytes[1]<<8)|bytes[0])+cpu.r.y;
var location_high_byte = (location & 0xff00)>>8;
var location_high_byte = location >> 8;
var location_low_byte = location & 0x00ff;
AND_absolute.execute(cpu, [location_low_byte, location_high_byte]);
}
@ -841,7 +951,7 @@ var SBC_absolute_indexed_x = {
},
execute:function(cpu, bytes) {
var location = ((bytes[1]<<8)|bytes[0])+cpu.r.x;
var location_high_byte = (location & 0xff00)>>8;
var location_high_byte = location >> 8;
var location_low_byte = location & 0x00ff;
SBC_absolute.execute(cpu, [location_low_byte, location_high_byte]);
}
@ -853,7 +963,7 @@ var SBC_absolute_indexed_y = {
},
execute:function(cpu, bytes) {
var location = ((bytes[1]<<8)|bytes[0])+cpu.r.y;
var location_high_byte = (location & 0xff00)>>8;
var location_high_byte = location >> 8;
var location_low_byte = location & 0x00ff;
SBC_absolute.execute(cpu, [location_low_byte, location_high_byte]);
}
@ -1002,7 +1112,7 @@ var ADC_absolute_indexed_x = {
},
execute:function(cpu, bytes) {
var location = ((bytes[1]<<8)|bytes[0])+cpu.r.x;
var location_high_byte = (location & 0xff00)>>8;
var location_high_byte = location >> 8;
var location_low_byte = location & 0x00ff;
ADC_absolute.execute(cpu, [location_low_byte, location_high_byte]);
}
@ -1014,7 +1124,7 @@ var ADC_absolute_indexed_y = {
},
execute:function(cpu, bytes) {
var location = ((bytes[1]<<8)|bytes[0])+cpu.r.y;
var location_high_byte = (location & 0xff00)>>8;
var location_high_byte = location >> 8;
var location_low_byte = location & 0x00ff;
ADC_absolute.execute(cpu, [location_low_byte, location_high_byte]);
}
@ -1447,7 +1557,7 @@ var STA_direct_page_indirect = {
var high_byte_loc = cpu.mmu.read_byte(location+1);
var absolute_location = (high_byte_loc<<8) | low_byte_loc;
var low_byte = cpu.r.a & 0x00ff;
var high_byte = (cpu.r.a & 0xff00)>>8;
var high_byte = cpu.r.a >> 8;
cpu.mmu.store_byte(absolute_location, low_byte);
cpu.mmu.store_byte(absolute_location+1, high_byte);
}
@ -1828,7 +1938,7 @@ var DEC_absolute = {
cpu.p.z = 0;
}
}
high_byte = (temp & 0xff00)>>8;
high_byte = temp >> 8;
low_byte = temp & 0x00ff;
cpu.mmu.store_byte(location, low_byte);
cpu.mmu.store_byte(location+1, high_byte);
@ -1876,7 +1986,7 @@ var DEC_direct_page = {
cpu.p.z = 0;
}
}
high_byte = (temp & 0xff00)>>8;
high_byte = temp >> 8;
low_byte = temp & 0x00ff;
cpu.mmu.store_byte(location, low_byte);
cpu.mmu.store_byte(location+1, high_byte);
@ -1974,7 +2084,7 @@ var INC_absolute = {
temp = (high_byte<<8) | low_byte;
temp++;
cpu.p.n = temp >> 15;
high_byte = (temp & 0xff00)>>8;
high_byte = temp >> 8;
low_byte = temp & 0x00ff;
cpu.mmu.store_byte(location, low_byte);
cpu.mmu.store_byte(location+1, high_byte);
@ -2010,7 +2120,7 @@ var INC_direct_page = {
temp = (high_byte<<8) | low_byte;
temp++;
cpu.p.n = temp >> 15;
high_byte = (temp & 0xff00)>>8;
high_byte = temp >> 8;
low_byte = temp & 0x00ff;
cpu.mmu.store_byte(location, low_byte);
cpu.mmu.store_byte(location+1, high_byte);
@ -2032,7 +2142,7 @@ var STA_direct_page_indexed_x = {
if(cpu.p.m) {
cpu.mmu.store_byte(location, cpu.r.a);
} else {
var high_byte = (cpu.r.a & 0xff00)>>8;
var high_byte = cpu.r.a >> 8;
var low_byte = cpu.r.a & 0x00ff;
// Check for overflow.
var overflow_check = location - 0xffff;
@ -2060,7 +2170,7 @@ var STA_direct_page = {
if(cpu.p.m) {
cpu.mmu.store_byte(location, cpu.r.a);
} else {
var high_byte = (cpu.r.a & 0xff00)>>8;
var high_byte = cpu.r.a >> 8;
var low_byte = cpu.r.a & 0x00ff;
cpu.mmu.store_byte(location, low_byte);
cpu.mmu.store_byte(location+1, high_byte);
@ -2077,7 +2187,7 @@ var STA_absolute_indexed_x = {
if(cpu.p.m) {
cpu.mmu.store_byte(location, cpu.r.a);
} else {
var high_byte = (cpu.r.a & 0xff00)>>8;
var high_byte = cpu.r.a >> 8;
var low_byte = cpu.r.a & 0x00ff;
cpu.mmu.store_byte(location, low_byte);
cpu.mmu.store_byte(location+1, high_byte);
@ -2094,7 +2204,7 @@ var STA_absolute_indexed_y = {
if(cpu.p.m) {
cpu.mmu.store_byte(location, cpu.r.a);
} else {
var high_byte = (cpu.r.a & 0xff00)>>8;
var high_byte = cpu.r.a >> 8;
var low_byte = cpu.r.a & 0x00ff;
cpu.mmu.store_byte(location, low_byte);
cpu.mmu.store_byte(location+1, high_byte);
@ -2111,7 +2221,7 @@ var STY_direct_page_indexed_x = {
if(cpu.p.x) {
cpu.mmu.store_byte(location, cpu.r.y);
} else {
var high_byte = (cpu.r.y & 0xff00)>>8;
var high_byte = cpu.r.y >> 8;
var low_byte = cpu.r.y & 0x00ff;
// Check for overflow.
var overflow_check = location - 0xffff;
@ -2139,7 +2249,7 @@ var STY_direct_page = {
if(cpu.p.x) {
cpu.mmu.store_byte(location, cpu.r.y);
} else {
var high_byte = (cpu.r.y & 0xff00)>>8;
var high_byte = cpu.r.y >> 8;
var low_byte = cpu.r.y & 0x00ff;
cpu.mmu.store_byte(location, low_byte);
cpu.mmu.store_byte(location+1, high_byte);
@ -2156,7 +2266,7 @@ var STY_absolute = {
if(cpu.p.x) {
cpu.mmu.store_byte(location, cpu.r.y);
} else {
var high_byte = (cpu.r.y & 0xff00)>>8;
var high_byte = cpu.r.y >> 8;
var low_byte = cpu.r.y & 0x00ff;
cpu.mmu.store_byte(location, low_byte);
cpu.mmu.store_byte(location+1, high_byte);
@ -2173,7 +2283,7 @@ var STX_direct_page_indexed_y = {
if(cpu.p.x===1) {
cpu.mmu.store_byte(location, cpu.r.x);
} else {
var high_byte = (cpu.r.x & 0xff00)>>8;
var high_byte = cpu.r.x >> 8;
var low_byte = cpu.r.x & 0x00ff;
// Check for overflow.
var overflow_check = location - 0xffff;
@ -2201,7 +2311,7 @@ var STX_direct_page = {
if(cpu.p.x) {
cpu.mmu.store_byte(location, cpu.r.x);
} else {
var high_byte = (cpu.r.x & 0xff00)>>8;
var high_byte = cpu.r.x >> 8;
var low_byte = cpu.r.x & 0x00ff;
cpu.mmu.store_byte(location, low_byte);
cpu.mmu.store_byte(location+1, high_byte);
@ -2218,7 +2328,7 @@ var STX_absolute = {
if(cpu.p.x) {
cpu.mmu.store_byte(location, cpu.r.x);
} else {
var high_byte = (cpu.r.x & 0xff00)>>8;
var high_byte = cpu.r.x >> 8;
var low_byte = cpu.r.x & 0x00ff;
cpu.mmu.store_byte(location, low_byte);
cpu.mmu.store_byte(location+1, high_byte);
@ -2235,7 +2345,7 @@ var STA_absolute_long = {
if(cpu.p.m) {
cpu.mmu.store_byte_long(location, bytes[2], cpu.r.a);
} else {
var high_byte = (cpu.r.a & 0xff00)>>8;
var high_byte = cpu.r.a >> 8;
var low_byte = cpu.r.a & 0x00ff;
cpu.mmu.store_byte_long(location, bytes[2], low_byte);
cpu.mmu.store_byte_long(location+1, bytes[2], high_byte);
@ -2252,7 +2362,7 @@ var STA_absolute = {
if(cpu.p.m) {
cpu.mmu.store_byte(location, cpu.r.a);
} else {
var high_byte = (cpu.r.a & 0xff00)>>8;
var high_byte = cpu.r.a >> 8;
var low_byte = cpu.r.a & 0x00ff;
cpu.mmu.store_byte(location, low_byte);
cpu.mmu.store_byte(location+1, high_byte);
@ -2542,7 +2652,7 @@ var XCE = {
cpu.p.e = temp;
if(cpu.p.e) {
// Switching to emulation mode.
var high_byte = (cpu.r.a & 0xff00)>>8;
var high_byte = cpu.r.a >> 8;
var low_byte = cpu.r.a & 0x00ff;
cpu.r.a = low_byte;
cpu.r.b = high_byte;