OR               Logical OR                          Flags: O D I T S Z A P C

0       * * ? * 0

OR destination,source

Logic:    destination   destination OR source

OR performs a bit-by-bit logical inclusive OR operation on its

operands and returns the result to destination.  The operands may be

words or bytes.

OR Instruction Logic

                   Destination  Source    Result

0         0         0

0         1         1

1         0         1

1         1         1

OR sets each bit of the result to 1 if either or both of the

corresponding bits of the operands are 1.

Operands                  Clocks   Transfers  Bytes   Example

                        byte(word)

register, register          3          -        2     OR CH,DL

register, memory        9(13) + EA     1       2-4    OR BX, MEM_OR_Y

memory, register       16(24) + EA     2       2-4    OR MEM_OR_Y, BX

accumulator, immediate      4          -       2-3    OR AL,01110110b

register,immediate          4          -       3-4    OR CX,00FFh

memory, immediate      17(25) + EA     2       3-6    OR MEM_WORD,76h

Prev:     NOT Logical NOT

See also: AND

See also: NOT

See also: XOR

See also: EA

See also: Flags

Next:     OUT Output to Port