πŸ”— Game Boy CPU (SM83) instruction set (JSON)

x0 x1 x2 x3 x4 x5 x6 x7
0x NOP 1  4 - - - - LD BC, d16 3  12 - - - - LD (BC), A 1  8 - - - - INC BC 1  8 - - - - INC B 1  4 Z 0 H - DEC B 1  4 Z 1 H - LD B, d8 2  8 - - - - RLCA 1  4 0 0 0 C
1x LD (a16), SP 3  20 - - - - ADD HL, BC 1  8 - 0 H C LD A, (BC) 1  8 - - - - DEC BC 1  8 - - - - INC C 1  4 Z 0 H - DEC C 1  4 Z 1 H - LD C, d8 2  8 - - - - RRCA 1  4 0 0 0 C
2x STOP d8 2  4 - - - - LD DE, d16 3  12 - - - - LD (DE), A 1  8 - - - - INC DE 1  8 - - - - INC D 1  4 Z 0 H - DEC D 1  4 Z 1 H - LD D, d8 2  8 - - - - RLA 1  4 0 0 0 C
3x JR r8 2  12 - - - - ADD HL, DE 1  8 - 0 H C LD A, (DE) 1  8 - - - - DEC DE 1  8 - - - - INC E 1  4 Z 0 H - DEC E 1  4 Z 1 H - LD E, d8 2  8 - - - - RRA 1  4 0 0 0 C
4x JR NZ, r8 2  12/8 - - - - LD HL, d16 3  12 - - - - LD (HL+), A 1  8 - - - - INC HL 1  8 - - - - INC H 1  4 Z 0 H - DEC H 1  4 Z 1 H - LD H, d8 2  8 - - - - DAA 1  4 Z - 0 C
5x JR Z, r8 2  12/8 - - - - ADD HL, HL 1  8 - 0 H C LD A, (HL+) 1  8 - - - - DEC HL 1  8 - - - - INC L 1  4 Z 0 H - DEC L 1  4 Z 1 H - LD L, d8 2  8 - - - - CPL 1  4 - 1 1 -
6x JR NC, r8 2  12/8 - - - - LD SP, d16 3  12 - - - - LD (HL-), A 1  8 - - - - INC SP 1  8 - - - - INC (HL) 1  12 Z 0 H - DEC (HL) 1  12 Z 1 H - LD (HL), d8 2  12 - - - - SCF 1  4 - 0 0 1
7x JR C, r8 2  12/8 - - - - ADD HL, SP 1  8 - 0 H C LD A, (HL-) 1  8 - - - - DEC SP 1  8 - - - - INC A 1  4 Z 0 H - DEC A 1  4 Z 1 H - LD A, d8 2  8 - - - - CCF 1  4 - 0 0 C
10x LD B, B 1  4 - - - - LD B, C 1  4 - - - - LD B, D 1  4 - - - - LD B, E 1  4 - - - - LD B, H 1  4 - - - - LD B, L 1  4 - - - - LD B, (HL) 1  8 - - - - LD B, A 1  4 - - - -
11x LD C, B 1  4 - - - - LD C, C 1  4 - - - - LD C, D 1  4 - - - - LD C, E 1  4 - - - - LD C, H 1  4 - - - - LD C, L 1  4 - - - - LD C, (HL) 1  8 - - - - LD C, A 1  4 - - - -
12x LD D, B 1  4 - - - - LD D, C 1  4 - - - - LD D, D 1  4 - - - - LD D, E 1  4 - - - - LD D, H 1  4 - - - - LD D, L 1  4 - - - - LD D, (HL) 1  8 - - - - LD D, A 1  4 - - - -
13x LD E, B 1  4 - - - - LD E, C 1  4 - - - - LD E, D 1  4 - - - - LD E, E 1  4 - - - - LD E, H 1  4 - - - - LD E, L 1  4 - - - - LD E, (HL) 1  8 - - - - LD E, A 1  4 - - - -
14x LD H, B 1  4 - - - - LD H, C 1  4 - - - - LD H, D 1  4 - - - - LD H, E 1  4 - - - - LD H, H 1  4 - - - - LD H, L 1  4 - - - - LD H, (HL) 1  8 - - - - LD H, A 1  4 - - - -
15x LD L, B 1  4 - - - - LD L, C 1  4 - - - - LD L, D 1  4 - - - - LD L, E 1  4 - - - - LD L, H 1  4 - - - - LD L, L 1  4 - - - - LD L, (HL) 1  8 - - - - LD L, A 1  4 - - - -
16x LD (HL), B 1  8 - - - - LD (HL), C 1  8 - - - - LD (HL), D 1  8 - - - - LD (HL), E 1  8 - - - - LD (HL), H 1  8 - - - - LD (HL), L 1  8 - - - - HALT 1  4 - - - - LD (HL), A 1  8 - - - -
17x LD A, B 1  4 - - - - LD A, C 1  4 - - - - LD A, D 1  4 - - - - LD A, E 1  4 - - - - LD A, H 1  4 - - - - LD A, L 1  4 - - - - LD A, (HL) 1  8 - - - - LD A, A 1  4 - - - -
20x ADD A, B 1  4 Z 0 H C ADD A, C 1  4 Z 0 H C ADD A, D 1  4 Z 0 H C ADD A, E 1  4 Z 0 H C ADD A, H 1  4 Z 0 H C ADD A, L 1  4 Z 0 H C ADD A, (HL) 1  8 Z 0 H C ADD A, A 1  4 Z 0 H C
21x ADC A, B 1  4 Z 0 H C ADC A, C 1  4 Z 0 H C ADC A, D 1  4 Z 0 H C ADC A, E 1  4 Z 0 H C ADC A, H 1  4 Z 0 H C ADC A, L 1  4 Z 0 H C ADC A, (HL) 1  8 Z 0 H C ADC A, A 1  4 Z 0 H C
22x SUB B 1  4 Z 1 H C SUB C 1  4 Z 1 H C SUB D 1  4 Z 1 H C SUB E 1  4 Z 1 H C SUB H 1  4 Z 1 H C SUB L 1  4 Z 1 H C SUB (HL) 1  8 Z 1 H C SUB A 1  4 1 1 0 0
23x SBC A, B 1  4 Z 1 H C SBC A, C 1  4 Z 1 H C SBC A, D 1  4 Z 1 H C SBC A, E 1  4 Z 1 H C SBC A, H 1  4 Z 1 H C SBC A, L 1  4 Z 1 H C SBC A, (HL) 1  8 Z 1 H C SBC A, A 1  4 Z 1 H C
24x AND B 1  4 Z 0 1 0 AND C 1  4 Z 0 1 0 AND D 1  4 Z 0 1 0 AND E 1  4 Z 0 1 0 AND H 1  4 Z 0 1 0 AND L 1  4 Z 0 1 0 AND (HL) 1  8 Z 0 1 0 AND A 1  4 Z 0 1 0
25x XOR B 1  4 Z 0 0 0 XOR C 1  4 Z 0 0 0 XOR D 1  4 Z 0 0 0 XOR E 1  4 Z 0 0 0 XOR H 1  4 Z 0 0 0 XOR L 1  4 Z 0 0 0 XOR (HL) 1  8 Z 0 0 0 XOR A 1  4 1 0 0 0
26x OR B 1  4 Z 0 0 0 OR C 1  4 Z 0 0 0 OR D 1  4 Z 0 0 0 OR E 1  4 Z 0 0 0 OR H 1  4 Z 0 0 0 OR L 1  4 Z 0 0 0 OR (HL) 1  8 Z 0 0 0 OR A 1  4 Z 0 0 0
27x CP B 1  4 Z 1 H C CP C 1  4 Z 1 H C CP D 1  4 Z 1 H C CP E 1  4 Z 1 H C CP H 1  4 Z 1 H C CP L 1  4 Z 1 H C CP (HL) 1  8 Z 1 H C CP A 1  4 1 1 0 0
30x RET NZ 1  20/8 - - - - POP BC 1  12 - - - - JP NZ, a16 3  16/12 - - - - JP a16 3  16 - - - - CALL NZ, a16 3  24/12 - - - - PUSH BC 1  16 - - - - ADD A, d8 2  8 Z 0 H C RST 00H 1  16 - - - -
31x RET Z 1  20/8 - - - - RET 1  16 - - - - JP Z, a16 3  16/12 - - - - PREFIX 1  4 - - - - CALL Z, a16 3  24/12 - - - - CALL a16 3  24 - - - - ADC A, d8 2  8 Z 0 H C RST 08H 1  16 - - - -
32x RET NC 1  20/8 - - - - POP DE 1  12 - - - - JP NC, a16 3  16/12 - - - - β€” CALL NC, a16 3  24/12 - - - - PUSH DE 1  16 - - - - SUB d8 2  8 Z 1 H C RST 10H 1  16 - - - -
33x RET C 1  20/8 - - - - RETI 1  16 - - - - JP C, a16 3  16/12 - - - - β€” CALL C, a16 3  24/12 - - - - β€” SBC A, d8 2  8 Z 1 H C RST 18H 1  16 - - - -
34x LDH (a8), A 2  12 - - - - POP HL 1  12 - - - - LD (C), A 1  8 - - - - β€” β€” PUSH HL 1  16 - - - - AND d8 2  8 Z 0 1 0 RST 20H 1  16 - - - -
35x ADD SP, r8 2  16 0 0 H C JP HL 1  4 - - - - LD (a16), A 3  16 - - - - β€” β€” β€” XOR d8 2  8 Z 0 0 0 RST 28H 1  16 - - - -
36x LDH A, (a8) 2  12 - - - - POP AF 1  12 Z N H C LD A, (C) 1  8 - - - - DI 1  4 - - - - β€” PUSH AF 1  16 - - - - OR d8 2  8 Z 0 0 0 RST 30H 1  16 - - - -
37x LD HL, SP + r8 2  12 0 0 H C LD SP, HL 1  8 - - - - LD A, (a16) 3  16 - - - - EI 1  4 - - - - β€” β€” CP d8 2  8 Z 1 H C RST 38H 1  16 - - - -

πŸ”— Prefixed ($CB $xx)

x0 x1 x2 x3 x4 x5 x6 x7
0x RLC B 2  8 Z 0 0 C RLC C 2  8 Z 0 0 C RLC D 2  8 Z 0 0 C RLC E 2  8 Z 0 0 C RLC H 2  8 Z 0 0 C RLC L 2  8 Z 0 0 C RLC (HL) 2  16 Z 0 0 C RLC A 2  8 Z 0 0 C
1x RRC B 2  8 Z 0 0 C RRC C 2  8 Z 0 0 C RRC D 2  8 Z 0 0 C RRC E 2  8 Z 0 0 C RRC H 2  8 Z 0 0 C RRC L 2  8 Z 0 0 C RRC (HL) 2  16 Z 0 0 C RRC A 2  8 Z 0 0 C
2x RL B 2  8 Z 0 0 C RL C 2  8 Z 0 0 C RL D 2  8 Z 0 0 C RL E 2  8 Z 0 0 C RL H 2  8 Z 0 0 C RL L 2  8 Z 0 0 C RL (HL) 2  16 Z 0 0 C RL A 2  8 Z 0 0 C
3x RR B 2  8 Z 0 0 C RR C 2  8 Z 0 0 C RR D 2  8 Z 0 0 C RR E 2  8 Z 0 0 C RR H 2  8 Z 0 0 C RR L 2  8 Z 0 0 C RR (HL) 2  16 Z 0 0 C RR A 2  8 Z 0 0 C
4x SLA B 2  8 Z 0 0 C SLA C 2  8 Z 0 0 C SLA D 2  8 Z 0 0 C SLA E 2  8 Z 0 0 C SLA H 2  8 Z 0 0 C SLA L 2  8 Z 0 0 C SLA (HL) 2  16 Z 0 0 C SLA A 2  8 Z 0 0 C
5x SRA B 2  8 Z 0 0 C SRA C 2  8 Z 0 0 C SRA D 2  8 Z 0 0 C SRA E 2  8 Z 0 0 C SRA H 2  8 Z 0 0 C SRA L 2  8 Z 0 0 C SRA (HL) 2  16 Z 0 0 C SRA A 2  8 Z 0 0 C
6x SWAP B 2  8 Z 0 0 0 SWAP C 2  8 Z 0 0 0 SWAP D 2  8 Z 0 0 0 SWAP E 2  8 Z 0 0 0 SWAP H 2  8 Z 0 0 0 SWAP L 2  8 Z 0 0 0 SWAP (HL) 2  16 Z 0 0 0 SWAP A 2  8 Z 0 0 0
7x SRL B 2  8 Z 0 0 C SRL C 2  8 Z 0 0 C SRL D 2  8 Z 0 0 C SRL E 2  8 Z 0 0 C SRL H 2  8 Z 0 0 C SRL L 2  8 Z 0 0 C SRL (HL) 2  16 Z 0 0 C SRL A 2  8 Z 0 0 C
10x BIT 0, B 2  8 Z 0 1 - BIT 0, C 2  8 Z 0 1 - BIT 0, D 2  8 Z 0 1 - BIT 0, E 2  8 Z 0 1 - BIT 0, H 2  8 Z 0 1 - BIT 0, L 2  8 Z 0 1 - BIT 0, (HL) 2  12 Z 0 1 - BIT 0, A 2  8 Z 0 1 -
11x BIT 1, B 2  8 Z 0 1 - BIT 1, C 2  8 Z 0 1 - BIT 1, D 2  8 Z 0 1 - BIT 1, E 2  8 Z 0 1 - BIT 1, H 2  8 Z 0 1 - BIT 1, L 2  8 Z 0 1 - BIT 1, (HL) 2  12 Z 0 1 - BIT 1, A 2  8 Z 0 1 -
12x BIT 2, B 2  8 Z 0 1 - BIT 2, C 2  8 Z 0 1 - BIT 2, D 2  8 Z 0 1 - BIT 2, E 2  8 Z 0 1 - BIT 2, H 2  8 Z 0 1 - BIT 2, L 2  8 Z 0 1 - BIT 2, (HL) 2  12 Z 0 1 - BIT 2, A 2  8 Z 0 1 -
13x BIT 3, B 2  8 Z 0 1 - BIT 3, C 2  8 Z 0 1 - BIT 3, D 2  8 Z 0 1 - BIT 3, E 2  8 Z 0 1 - BIT 3, H 2  8 Z 0 1 - BIT 3, L 2  8 Z 0 1 - BIT 3, (HL) 2  12 Z 0 1 - BIT 3, A 2  8 Z 0 1 -
14x BIT 4, B 2  8 Z 0 1 - BIT 4, C 2  8 Z 0 1 - BIT 4, D 2  8 Z 0 1 - BIT 4, E 2  8 Z 0 1 - BIT 4, H 2  8 Z 0 1 - BIT 4, L 2  8 Z 0 1 - BIT 4, (HL) 2  12 Z 0 1 - BIT 4, A 2  8 Z 0 1 -
15x BIT 5, B 2  8 Z 0 1 - BIT 5, C 2  8 Z 0 1 - BIT 5, D 2  8 Z 0 1 - BIT 5, E 2  8 Z 0 1 - BIT 5, H 2  8 Z 0 1 - BIT 5, L 2  8 Z 0 1 - BIT 5, (HL) 2  12 Z 0 1 - BIT 5, A 2  8 Z 0 1 -
16x BIT 6, B 2  8 Z 0 1 - BIT 6, C 2  8 Z 0 1 - BIT 6, D 2  8 Z 0 1 - BIT 6, E 2  8 Z 0 1 - BIT 6, H 2  8 Z 0 1 - BIT 6, L 2  8 Z 0 1 - BIT 6, (HL) 2  12 Z 0 1 - BIT 6, A 2  8 Z 0 1 -
17x BIT 7, B 2  8 Z 0 1 - BIT 7, C 2  8 Z 0 1 - BIT 7, D 2  8 Z 0 1 - BIT 7, E 2  8 Z 0 1 - BIT 7, H 2  8 Z 0 1 - BIT 7, L 2  8 Z 0 1 - BIT 7, (HL) 2  12 Z 0 1 - BIT 7, A 2  8 Z 0 1 -
20x RES 0, B 2  8 - - - - RES 0, C 2  8 - - - - RES 0, D 2  8 - - - - RES 0, E 2  8 - - - - RES 0, H 2  8 - - - - RES 0, L 2  8 - - - - RES 0, (HL) 2  16 - - - - RES 0, A 2  8 - - - -
21x RES 1, B 2  8 - - - - RES 1, C 2  8 - - - - RES 1, D 2  8 - - - - RES 1, E 2  8 - - - - RES 1, H 2  8 - - - - RES 1, L 2  8 - - - - RES 1, (HL) 2  16 - - - - RES 1, A 2  8 - - - -
22x RES 2, B 2  8 - - - - RES 2, C 2  8 - - - - RES 2, D 2  8 - - - - RES 2, E 2  8 - - - - RES 2, H 2  8 - - - - RES 2, L 2  8 - - - - RES 2, (HL) 2  16 - - - - RES 2, A 2  8 - - - -
23x RES 3, B 2  8 - - - - RES 3, C 2  8 - - - - RES 3, D 2  8 - - - - RES 3, E 2  8 - - - - RES 3, H 2  8 - - - - RES 3, L 2  8 - - - - RES 3, (HL) 2  16 - - - - RES 3, A 2  8 - - - -
24x RES 4, B 2  8 - - - - RES 4, C 2  8 - - - - RES 4, D 2  8 - - - - RES 4, E 2  8 - - - - RES 4, H 2  8 - - - - RES 4, L 2  8 - - - - RES 4, (HL) 2  16 - - - - RES 4, A 2  8 - - - -
25x RES 5, B 2  8 - - - - RES 5, C 2  8 - - - - RES 5, D 2  8 - - - - RES 5, E 2  8 - - - - RES 5, H 2  8 - - - - RES 5, L 2  8 - - - - RES 5, (HL) 2  16 - - - - RES 5, A 2  8 - - - -
26x RES 6, B 2  8 - - - - RES 6, C 2  8 - - - - RES 6, D 2  8 - - - - RES 6, E 2  8 - - - - RES 6, H 2  8 - - - - RES 6, L 2  8 - - - - RES 6, (HL) 2  16 - - - - RES 6, A 2  8 - - - -
27x RES 7, B 2  8 - - - - RES 7, C 2  8 - - - - RES 7, D 2  8 - - - - RES 7, E 2  8 - - - - RES 7, H 2  8 - - - - RES 7, L 2  8 - - - - RES 7, (HL) 2  16 - - - - RES 7, A 2  8 - - - -
30x SET 0, B 2  8 - - - - SET 0, C 2  8 - - - - SET 0, D 2  8 - - - - SET 0, E 2  8 - - - - SET 0, H 2  8 - - - - SET 0, L 2  8 - - - - SET 0, (HL) 2  16 - - - - SET 0, A 2  8 - - - -
31x SET 1, B 2  8 - - - - SET 1, C 2  8 - - - - SET 1, D 2  8 - - - - SET 1, E 2  8 - - - - SET 1, H 2  8 - - - - SET 1, L 2  8 - - - - SET 1, (HL) 2  16 - - - - SET 1, A 2  8 - - - -
32x SET 2, B 2  8 - - - - SET 2, C 2  8 - - - - SET 2, D 2  8 - - - - SET 2, E 2  8 - - - - SET 2, H 2  8 - - - - SET 2, L 2  8 - - - - SET 2, (HL) 2  16 - - - - SET 2, A 2  8 - - - -
33x SET 3, B 2  8 - - - - SET 3, C 2  8 - - - - SET 3, D 2  8 - - - - SET 3, E 2  8 - - - - SET 3, H 2  8 - - - - SET 3, L 2  8 - - - - SET 3, (HL) 2  16 - - - - SET 3, A 2  8 - - - -
34x SET 4, B 2  8 - - - - SET 4, C 2  8 - - - - SET 4, D 2  8 - - - - SET 4, E 2  8 - - - - SET 4, H 2  8 - - - - SET 4, L 2  8 - - - - SET 4, (HL) 2  16 - - - - SET 4, A 2  8 - - - -
35x SET 5, B 2  8 - - - - SET 5, C 2  8 - - - - SET 5, D 2  8 - - - - SET 5, E 2  8 - - - - SET 5, H 2  8 - - - - SET 5, L 2  8 - - - - SET 5, (HL) 2  16 - - - - SET 5, A 2  8 - - - -
36x SET 6, B 2  8 - - - - SET 6, C 2  8 - - - - SET 6, D 2  8 - - - - SET 6, E 2  8 - - - - SET 6, H 2  8 - - - - SET 6, L 2  8 - - - - SET 6, (HL) 2  16 - - - - SET 6, A 2  8 - - - -
37x SET 7, B 2  8 - - - - SET 7, C 2  8 - - - - SET 7, D 2  8 - - - - SET 7, E 2  8 - - - - SET 7, H 2  8 - - - - SET 7, L 2  8 - - - - SET 7, (HL) 2  16 - - - - SET 7, A 2  8 - - - -
Misc / control instructions Jumps / calls 8-bit load instructions 16-bit load instructions 8-bit arithmetic / logical instructions 16-bit arithmetic / logical instructions 8-bit shift, rotate and bit instructions
INS reg
← Instruction mnemonic
Length in bytes β†’ 2  8
← Duration in T-states*
Z N H C ← Flags affected

*) Often instruction durations are given in β€œM-cycles” (machine cycles) instead of β€œT-states” (system clock ticks) because each instruction takes a multiple of four T-states to complete, thus a NOP takes one M-cycle or four T-states to complete.

Z - Zero Flag
N - Subtract Flag
H - Half Carry Flag
C - Carry Flag
0 - The flag is reset
1 - The flag is set
- - The flag is left untouched

If an operation has the flags defined as Z, N, H, or C, the corresponding flags are set as the operation performed dictates.

The duration of conditional calls and returns is different when action is taken or not. This is indicated by two numbers separated by β€œ/”. The higher number (on the left side of β€œ/”) is the duration of the instruction when action is taken, the lower number (on the right side of β€œ/”) is the duration of the instruction when action is not taken.
STOP: The opcode of this instruction is $10, but it has to be followed by an additional byte that is ignored by the CPU (any value works, but normally $00 is used).

d8 means immediate 8-bit data

d16 means immediate little-endian 16-bit data

a8 means 8-bit unsigned data, which is added to $FF00 in certain instructions (replacement for missing IN and OUT instructions)

a16 means little-endian 16-bit address

r8 means 8-bit signed data

LD A, (C) has the alternative mnemonic LD A, ($FF00+C)

LD (C), A has the alternative mnemonic LD ($FF00+C), A

LDH A, (a8) has the alternative mnemonic LD A, ($FF00+a8)

LDH (a8), A has the alternative mnemonic LD ($FF00+a8), A

LD A, (HL+) has the alternative mnemonic LD A, (HLI) or LDI A, (HL)

LD (HL+), A has the alternative mnemonic LD (HLI), A or LDI (HL), A

LD A, (HL-) has the alternative mnemonic LD A, (HLD) or LDD A, (HL)

LD (HL-), A has the alternative mnemonic LD (HLD), A or LDD (HL), A

LD HL, SP+r8 has the alternative mnemonic LDHL SP, r8