INC 8-bit Increment
Increment 8-bit register by 1
| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | |
|---|---|---|---|---|---|---|---|---|
| \(s \longleftarrow r + 1\) | ||||||||
| INC r | ||||||||
| 0 | 0 | r | 1 | 0 | 0 | |||
| \((HL) \longleftarrow (HL) + 1\) | ||||||||
| INC (HL) | ||||||||
| 0 | 0 | 1 | 1 | 0 | 1 | 0 | 0 | 34 |
| \((IX+d) \longleftarrow (IX+d) + 1\) | ||||||||
| INC (IX+d) | ||||||||
| 1 | 1 | 0 | 1 | 1 | 1 | 0 | 1 | DD |
| 0 | 0 | 1 | 1 | 0 | 1 | 0 | 0 | 34 |
| d | ||||||||
| \((IY+d) \longleftarrow (IY+d) + 1\) | ||||||||
| INC (IY+d) | ||||||||
| 1 | 1 | 1 | 1 | 1 | 1 | 0 | 1 | FD |
| 0 | 0 | 1 | 1 | 0 | 1 | 0 | 0 | 34 |
| d | ||||||||
| Register | r |
|---|---|
| B | 000 |
| C | 001 |
| D | 010 |
| E | 011 |
| H | 100 |
| L | 101 |
| A | 111 |
Flags Affected
| Flags |
| ||||||||
|---|---|---|---|---|---|---|---|---|---|
| s | set if result negative | ||||||||
| z | set if result is 0 | ||||||||
| h | set if carry from bit 3 | ||||||||
| p/v | set if register was 0x7F before operation, reset otherwise |
Opcode Matrix
| A | B | C | D | E | H | L | (HL) | (IX+d) | (IY+d) | |
|---|---|---|---|---|---|---|---|---|---|---|
| Op |
INC A
3C14 |
INC B
0414 |
INC C
0C14 |
INC D
1414 |
INC E
1C14 |
INC H
2414 |
INC L
2C14 |
INC (HL)
34111 |
INC (IX+d)
DD34nn323 |
INC (IY+d)
FD34nn323 |
|
Instruction
Opcode hexSize bytesCycle count
| Register | Memory |
Last modified November 16, 2021: Add flags to math operations (63d34c2)