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

added the rest of the addressing modes for BIT and fixed a bug in a few operations

This commit is contained in:
Preston Skupinski 2011-05-30 19:22:19 -04:00
parent 71552b5720
commit c9d491411b
2 changed files with 89 additions and 12 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
TODO
View File

@ -12,10 +12,6 @@ Operations Not Yet Implemented:
- 0x0c : TSB absolute
- 0x14 : TRB direct page
- 0x1c : TRB absolute
- 0x24 : BIT direct page
- 0x2c : BIT absolute
- 0x34 : BIT direct page indexed x
- 0x3c : BIT absolute indexed x
- 0x42 : WDM
- 0x5c : JMP absolute long
- 0x7c : JMP absolute indexed x indirect

97
cpu.js
View File

@ -205,7 +205,10 @@ function CPU_65816() {
0x4b : PHK, 0x0b : PHD, 0x2b : PLD, 0x62 : PER,
0x20 : JSR, 0x60 : RTS, 0x22 : JSL, 0x6b : RTL,
0x54 : MVN, 0x44 : MVP, 0x00 : BRK, 0x40 : RTI,
0x02 : COP, 0x89 : BIT_const };
0x02 : COP, 0x89 : BIT_const, 0x2c : BIT_absolute,
0x24 : BIT_direct_page,
0x3c : BIT_absolute_indexed_x,
0x34 : BIT_direct_page_indexed_x };
/**
* Take a raw hex string representing the program and execute it.
@ -423,7 +426,7 @@ var MMU = {
var BIT_const = {
bytes_required:function(cpu) {
if(cpu.p.m)
if(cpu.p.e|cpu.p.m)
return 2;
else
return 3;
@ -449,6 +452,84 @@ var BIT_const = {
}
};
var BIT_absolute = {
bytes_required:function() {
return 3;
},
execute:function(cpu, bytes) {
var location = (bytes[1]<<8)|bytes[0];
if(cpu.p.e|cpu.p.m) {
BIT_const.execute(cpu, [cpu.mmu.read_byte(location)]);
} else {
var low_byte = cpu.mmu.read_byte(location);
var high_byte = cpu.mmu.read_byte(location+1);
BIT_const.execute(cpu, [low_byte, high_byte]);
}
}
};
var BIT_direct_page = {
bytes_required:function() {
return 2;
},
execute:function(cpu, bytes) {
var location = bytes[0] + cpu.r.d;
if(cpu.p.e|cpu.p.m) {
BIT_const.execute(cpu, [cpu.mmu.read_byte(location)]);
} else {
var low_byte = cpu.mmu.read_byte(location);
var high_byte = cpu.mmu.read_byte(location+1);
BIT_const.execute(cpu, [low_byte, high_byte]);
}
}
};
var BIT_direct_page_indexed_x = {
bytes_required:function() {
return 2;
},
execute:function(cpu, bytes) {
if(cpu.p.e) {
var location = (bytes[0] + cpu.r.x) & 0xff;
var low_byte_loc = cpu.mmu.read_byte_long((location+cpu.r.d)&0xffff, 0);
var high_byte_loc = cpu.mmu.read_byte_long((((location+1)&0xff)+cpu.r.d)&0xffff, 0);
BIT_const.execute(cpu, [cpu.mmu.read_byte((high_byte_loc<<8) | low_byte_loc)]);
} else if(cpu.p.m) {
var location = bytes[0] + cpu.r.d + cpu.r.x;
var low_byte_loc = cpu.mmu.read_byte(location);
var high_byte_loc = cpu.mmu.read_byte((location+1)&0xffff);
BIT_const.execute(cpu, [cpu.mmu.read_byte((high_byte_loc<<8)|low_byte_loc)]);
} else {
var location = bytes[0] + cpu.r.d + cpu.r.x;
var low_byte_loc = cpu.mmu.read_byte(location);
var high_byte_loc = cpu.mmu.read_byte((location+1)&0xffff);
var absolute_location = (high_byte_loc<<8) | low_byte_loc;
var low_byte = cpu.mmu.read_byte(absolute_location);
var high_byte;
absolute_location++;
if(absolute_location&0x10000) {
absolute_location &= 0xffff;
high_byte = cpu.mmu.read_byte_long(absolute_location, cpu.r.dbr+1);
} else {
high_byte = cpu.mmu.read_byte(absolute_location);
}
BIT_const.execute(cpu, [low_byte, high_byte]);
}
}
};
var BIT_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;
BIT_absolute.execute(cpu, [location_low_byte, location_high_byte]);
}
};
var COP = {
bytes_required:function() {
return 2;
@ -1448,7 +1529,7 @@ var EOR_direct_page = {
execute:function(cpu, bytes) {
var location = bytes[0] + cpu.r.d;
if(cpu.p.e|cpu.p.m) {
EOR_const.execute(cpu, cpu.mmu.read_byte(location));
EOR_const.execute(cpu, [cpu.mmu.read_byte(location)]);
} else {
var low_byte = cpu.mmu.read_byte(location);
var high_byte = cpu.mmu.read_byte(location+1);
@ -1779,7 +1860,7 @@ var ORA_direct_page = {
execute:function(cpu, bytes) {
var location = bytes[0] + cpu.r.d;
if(cpu.p.e|cpu.p.m) {
ORA_const.execute(cpu, cpu.mmu.read_byte(location));
ORA_const.execute(cpu, [cpu.mmu.read_byte(location)]);
} else {
var low_byte = cpu.mmu.read_byte(location);
var high_byte = cpu.mmu.read_byte(location+1);
@ -2110,7 +2191,7 @@ var AND_direct_page = {
execute:function(cpu, bytes) {
var location = bytes[0] + cpu.r.d;
if(cpu.p.e|cpu.p.m) {
AND_const.execute(cpu, cpu.mmu.read_byte(location));
AND_const.execute(cpu, [cpu.mmu.read_byte(location)]);
} else {
var low_byte = cpu.mmu.read_byte(location);
var high_byte = cpu.mmu.read_byte(location+1);
@ -2396,7 +2477,7 @@ var CPX_direct_page = {
execute:function(cpu, bytes) {
var location = bytes[0] + cpu.r.d;
if(cpu.p.e|cpu.p.m) {
CPX_const.execute(cpu, cpu.mmu.read_byte(location));
CPX_const.execute(cpu, [cpu.mmu.read_byte(location)]);
} else {
var low_byte = cpu.mmu.read_byte(location);
var high_byte = cpu.mmu.read_byte(location+1);
@ -2466,7 +2547,7 @@ var CPY_direct_page = {
execute:function(cpu, bytes) {
var location = bytes[0] + cpu.r.d;
if(cpu.p.e|cpu.p.m) {
CPY_const.execute(cpu, cpu.mmu.read_byte(location));
CPY_const.execute(cpu, [cpu.mmu.read_byte(location)]);
} else {
var low_byte = cpu.mmu.read_byte(location);
var high_byte = cpu.mmu.read_byte(location+1);
@ -2536,7 +2617,7 @@ var CMP_direct_page = {
execute:function(cpu, bytes) {
var location = bytes[0] + cpu.r.d;
if(cpu.p.e|cpu.p.m) {
CMP_const.execute(cpu, cpu.mmu.read_byte(location));
CMP_const.execute(cpu, [cpu.mmu.read_byte(location)]);
} else {
var low_byte = cpu.mmu.read_byte(location);
var high_byte = cpu.mmu.read_byte(location+1);