Panasonic MN103001G/F01K User Manual

Page 84

Extension Instruction Specifications

3-28

SWAP (Data swapping instruction that swaps bytes [high-order to low-order and vice versa] in four-byte data)

[Instruction Format (Macro Name)]

SWAP

Dm, Dn

[Assembler Mnemonic]

udf08

Dm, Dn

[Operation]

This instruction swaps the positions of the high-order and low-order 8-bit bytes within the respective high- and

low-order 16-bit half-words within the 32-bit data stored in Dm, and then swaps the positions of the high-order and

low-order 16-bit half-words, and then stores the result in Dn. As a result, bits 31 through 24 of Dm are stored in bits

7 through 0 in Dn, bits 23 through 16 of Dm are stored in bits 15 through 8 in Dn, bits 15 through 8 of Dm are stored

in bits 23 through 16 in Dn, and bits 7 through 0 of Dm are stored in bits 31 through 24 in Dn.

The sample of execution

Before execution:

0x12345678

After execution:

0x78563412

Bit 31

Bit 0

MSB

LSB

Dm before execution

Dn after execution

Dm[31:24]

Dm[23:16]

Dm[15:8]

Dm[7:0]