6502/65816.js
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added JMP absolute indexed x indirect

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Preston Skupinski 2011-06-12 18:54:16 -04:00
parent 26fddd8943
commit a9e15285cb
2 changed files with 29 additions and 1 deletions
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1
TODO
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@ -8,7 +8,6 @@ Testing:
- Tests needed for interrupt support - Tests needed for interrupt support
- Tests needed for the numerous other operations added - Tests needed for the numerous other operations added
Operations Not Yet Implemented: Operations Not Yet Implemented:
- 0x7c : JMP absolute indexed x indirect
- 0xcb : WAI - 0xcb : WAI
- 0xdb : STP - 0xdb : STP
- 0xfc : JSR absolute indexed x indirect - 0xfc : JSR absolute indexed x indirect

29
cpu.js
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@ -102,6 +102,7 @@ function CPU_65816() {
0x3b : TSC, 0x4c : JMP_absolute, 0x3b : TSC, 0x4c : JMP_absolute,
0x5c : JMP_absolute_long, 0x5c : JMP_absolute_long,
0xdc : JMP_absolute_indirect_long, 0xdc : JMP_absolute_indirect_long,
0x7c : JMP_absolute_indexed_x_indirect,
0x6c : JMP_absolute_indirect, 0x80 : BRA, 0x82 : BRL, 0x6c : JMP_absolute_indirect, 0x80 : BRA, 0x82 : BRL,
0xf0 : BEQ, 0xd0 : BNE, 0x90 : BCC, 0xb0 : BCS, 0xf0 : BEQ, 0xd0 : BNE, 0x90 : BCC, 0xb0 : BCS,
0x50 : BVC, 0x70 : BVS, 0x10 : BPL, 0x30 : BMI, 0x50 : BVC, 0x70 : BVS, 0x10 : BPL, 0x30 : BMI,
@ -4036,6 +4037,34 @@ var JMP_absolute_indirect_long = {
} }
}; };
var JMP_absolute_indexed_x_indirect = {
bytes_required:function() {
return 3;
},
execute:function(cpu, bytes) {
var location = ((bytes[1]<<8)|bytes[0])+cpu.r.x;
var bank = cpu.r.k;
if(location&0x10000) {
bank++;
}
location &= 0xffff;
var indirect_location_low_byte = cpu.mmu.read_byte_long(location, bank);
var indirect_location_high_byte = cpu.mmu.read_byte_long(location+1, bank);
var indirect_location = (indirect_location_high_byte<<8) |
indirect_location_low_byte;
var low_byte = cpu.mmu.read_byte(indirect_location);
bank = cpu.r.k;
if(indirect_location===0xffff) {
indirect_location = 0;
bank++;
} else {
indirect_location++;
}
var high_byte = cpu.mmu.read_byte_long(indirect_location, bank);
cpu.r.pc = (high_byte<<8)|low_byte;
}
};
var JMP_absolute = { var JMP_absolute = {
bytes_required:function() { bytes_required:function() {
return 3; return 3;