ADC

The sum of the two operands plus the carry flag (0 or 1) is calculated, and the result is written back into the first operand.

## Syntax

```
adc a,op8 ;8 bit
adc hl,op16 ;16 bit
```

### Allowed instructions

```
adc a,a
adc a,b
adc a,c
adc a,d
adc a,e
adc a,h
adc a,l
adc a,ixh
adc a,ixl
adc a,iyh
adc a,iyl
adc a,(hl)
adc a,(ix+n)
adc a,(iy+n)
adc a,n ;(8-bit number)
adc hl,bc
adc hl,de
adc hl,hl
adc hl,sp
```

## Effects

The N flag is reset, P/V is interpreted as overflow. The rest of the flags is modified by definition. In the case of 16-bit addition the H flag is undefined.

## Uses

Multiple precision adding

## T-States

r denotes 8-bit register.

rr represents a two byte register pair: BC, DE, HL, SP

a, r | 4 |

a, X | 7 |

a, (hl) | 7 |

a, (ix+X) | 19 |

a, (iy+X) | 19 |

hl, rr | 15 |

## See also

page revision: 16, last edited: 31 Oct 2014 13:30