S3C84E5/C84E9/P84E9

INSTRUCTION SET

 

 

RR — Rotate Right

RRdst

Operation: C dst (0)

dst (7) dst (0)

dst (n) dst (n + 1), n = 0–6

The contents of the destination operand are rotated right one bit position. The initial value of bit zero (LSB) is moved to bit 7 (MSB) and also replaces the carry flag (C).

C

7

0

Flags:

C:

Set if the bit rotated from the least significant bit position (bit zero) was "1".

 

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

 

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

 

V: Set if arithmetic overflow occurred, that is, if the sign of the destination is changed during

 

 

the rotation; cleared otherwise.

 

D:

Unaffected.

 

H:

Unaffected.

Format:

 

Bytes Cycles Opcode

Addr Mode

(Hex)

dst

opc

dst

2

4

E0

R

 

4

E1

IR

Examples:

Given:

Register 00H

= 31H, register 01H = 02H, and register 02H = 17H:

 

RR

00H

Register 00H =

98H, C = "1"

 

RR

@01H

Register 01H =

02H, register 02H = 8BH, C = "1"

In the first example, if the general register 00H contains the value 31H (00110001B), the statement "RR 00H" rotates this value one bit position to the right. The initial value of bit zero is moved to bit 7, leaving the new value 98H (10011000B) in the destination register. The initial bit zero also resets the C flag to "1" and the sign flag and the overflow flag are also set to "1".

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Samsung S3C84E5 user manual RR Rotate Right, RRdst Operation C ← dst