6502/65816.js
1
0
Fork 0
mirror of https://github.com/pskupinski/65816.js.git synced 2024-06-11 00:29:31 +00:00
Code Issues Projects Releases Wiki Activity

added PEA and PEI

Browse Source
This commit is contained in:
Preston Skupinski 2011-05-09 00:01:16 -04:00
parent 98a058058f
commit b956d2254f
1 changed files with 27 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

30
cpu.js
View File

@ -124,7 +124,8 @@ function CPU_65816() {
0x7e : ROR_absolute_indexed_x,
0x76 : ROR_direct_page_indexed_x,
0x48 : PHA , 0x68 : PLA, 0x5a : PHY, 0x7a : PLY,
0xda : PHX, 0xfa : PLX, 0x08 : PHP, 0x28 : PLP };
0xda : PHX, 0xfa : PLX, 0x08 : PHP, 0x28 : PLP,
0xf4 : PEA, 0xd4 : PEI };
/**
* Take a raw hex string representing the program and execute it.
@ -203,6 +204,29 @@ var MMU = {
}
};
var PEA = {
bytes_required:function() {
return 3;
},
execute:function(cpu, bytes) {
cpu.mmu.store_byte(cpu.r.s--, bytes[0]);
cpu.mmu.store_byte(cpu.r.s--, bytes[1]);
}
};
var PEI = {
bytes_required:function() {
return 2;
},
execute:function(cpu, bytes) {
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);
}
};
var PHP = {
bytes_required:function() {
return 1;
@ -244,7 +268,7 @@ var PHX = {
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--, high_byte);
cpu.mmu.store_byte(cpu.r.s--, low_byte);
}
}
};
@ -283,7 +307,7 @@ var PHY = {
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--, high_byte);
cpu.mmu.store_byte(cpu.r.s--, low_byte);
}
}
};