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MICROPROCESSOR INSTRUCTION REFERENCE->DA

DA             Decimal Adjust Accumulator

DA adjust the eight bit value in the accumulator resulting from the earlier addition of two variable (each in packed-BCD format), producing two four bit digits.  Any ADD or ADDC instruction may have been used to perform the addition.

If the contents of bits 0-3 are greater than nine or the auxiliary carry is set, the accumulator is incremented by six.

The four high-order bits are then checked and if bits 4-7 exceed nine or the carry is set, these bits are increased by six.

If an overflow occurs, the carry is set.


Formats:
    

Description	Mnemonic	Bytes	Cycles

Decimal adjust accumulator:

DA A

1

1