Intel 8XC251SA, User Manual

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A-129
INSTRUCTION SET REFERENCE
SWAP A
Function: Swap nibbles within the accumulator
Description: Interchanges the low and high nibbles (4-bit fields) of the accumulator (bits 3–0 and bits 7–
4). This operation can also be thought of as a 4-bit rotate instruction.
Flags:
Example: The accumulator contains 0C5H (11000101B). After executing the instruction
SWAP A
the accumulator contains 5CH (01011100B).
Binary Mode Source Mode
Bytes: 1 1
States: 2 2
Hex Code in: Binary Mode = [Encoding]
Source Mode = [Encoding]
Operation: SWAP
(A).3:0
→ ←
(A).7:4
TRAP
Function: Causes interrupt call
Description: Causes an interrupt call that is vectored through location 0FF007BH. The operation of this
instruction is not affected by the state of the interrupt enable flag in PSW0 and PSW1.
Interrupt calls can not occur immediately following this instruction. This instruction is
intended for use by Intel-provided development tools. These tools do not support user
application of this instruction.
Flags:
Example: The instruction
TRAP
causes an interrupt call to location 0FF007BH during normal operation.
CY AC OV N Z
— — — — —
[Encoding] 1 1 0 0 0 1 0 0
CY AC OV N Z
— — — — —