Samsung S3F80JB manual Swap Swap Nibbles, Swap dst, 00H Register 00H 0E3H

Models: S3F80JB

1 346
Download 346 pages 34.13 Kb
Page 211
Image 211

S3F80JBINSTRUCTION SET

SWAP — Swap Nibbles

SWAP dst

Operation: dst (0 – 3) dst (4 – 7)

The contents of the lower four bits and upper four bits of the destination operand are swapped.

7

4 3

0

Flags:

C:

Undefined.

 

Z:

Set if the result is "0"; cleared otherwise.

 

S:

Set if the result bit 7 is set; cleared otherwise.

 

V:

Undefined.

 

D:

Unaffected.

 

H:

Unaffected.

Format:

 

Bytes Cycles Opcode

Addr Mode

(Hex)

dst

opc

dst

2

4

F0

R

 

4

F1

IR

Examples: Given: Register 00H = 3EH, register 02H = 03H, and register 03H = 0A4H:

SWAP

00H

Register 00H

=

0E3H

SWAP

@02H

Register 02H

=

03H, register 03H = 4AH

In the first example, if general register 00H contains the value 3EH (00111110B), the statement "SWAP 00H" swaps the lower and upper four bits (nibbles) in the 00H register, leaving the value 0E3H (11100011B).

6-83

Page 211
Image 211
Samsung S3F80JB manual Swap Swap Nibbles, Swap dst, Flags Undefined Set if the result is 0 cleared otherwise