6502 opcodes

From Data Crystal
Jump to navigation Jump to search

The following table contains a list of opcodes for the 6502 processor, as used in the NES. (this list is incomplete; for a full list of opcodes used by the 6502, including undocumented and illegal instructions, see http://www.oxyron.de/html/opcodes02.html)

  • ABS = Absolute
  • ACC = Accumulator
  • IMM = Immediate
  • IND = Indirect

Mnemonic Description Implied / ACC (IND),X (IND,Y) ABS ABS,X IMM ABS,Y Zero Page Zero Page,X
ADC add memory to accumulator with carry 61 71 6D 7D 69 79 65 75
AND AND memory with accumulator 21 31 2D 3D 29 39 25 35
ASL shift left one bit (memory or accumulator) 0A 06 16
BCC branch on carry clear 90
BCS branch on carry set B0
BEQ branch on result zero F0
BIT test bits in memory with accumulator 2C 24
BMI branch on result minus 30
BNE branch on result not zero D0
BPL branch on result plus 10
BVC branch on overflow clear 50
BVS branch on overflow set 70
CLC clear carry flag 18
CLD clear decimal mode D8
CLI clear interrupt disable bit 58
CLV clear overflow flag B8
CMP compare memory and accumulator C1 D1 CD DD C9 D9 C5 D5
CPX compare memory and X register EC E0 E4
CPY compare memory and Y register CC C0 C4
Mnemonic Description Implied / ACC (IND),X (IND,Y) ABS ABS,X IMM ABS,Y Zero Page Zero Page,X
DEC decrement memory CE DE C6 D6
DEX decrement X register CA
DEY decrement Y register 88
EOR EXCLUSIVE OR memory with accumulator 41 51 4D 5D 49 59 45 55
INC increment memory EE FE E6 F6
INX increment X register E8
INY increment Y register C8
JMP jump to new location 6C 4C
JSR jump to new location saving return address 20
LDA load accumulator with memory A1 B1 AD BD A9 B9 A5 B5
LDX load X register with memory AE A2 BE A6 B6
LDY load Y register with memory AC BC A0 A4 B4
LSR shift right one bit (memory or accumulator) 4A 4E 5E 46
NOP no operation EA
ORA OR memory with accumulator 01 11 0D 1D 09 19 05 15
PHA push accumulator on stack 48
PHP push processor status on stack 08
PLA pull accumulator from from stack 68
PLP pull processor status from stack 28
Mnemonic Description Implied / ACC (IND),X (IND,Y) ABS ABS,X IMM ABS,Y Zero Page Zero Page,X
ROL rotate one bit left (memory or accumulator) 2A 2E 26 36
ROR rotate one bit right (memory or accumulator) 6A 6E 7E 66 76
RTI return from interrupt 40
RTS return from subroutine 60
SBC subtract memory from accumulator with borrow E1 F1 ED FD E9 F9 E5 F5
SEC set carry flag 38
SED set decimal mode F8
SEI set interrupt disable bit 78
STA store accumulator in memory 81 91 8D 9D 99 85 95
STX store X register in memory 8E 86 96
STY store Y register in memory 8C 84 94
TAX transfer accumulator to X register AA
TAY transfer accumulator to Y register A8
TSX transfer stack pointer to X register BA
TXA transfer X register to accumulator 8A
TXS transfer X register to stack pointer 9A
TYA transfer Y register to accumulator 98