INSTRUCTION SET

S3C84E5/C84E9/P84E9

 

 

RRC — Rotate Right through Carry

RRCdst

Operation: dst (7) C

C dst (0)

dst (n) dst (n + 1), n = 0–6

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

7

0

C

 

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

C0

R

 

4

C1

IR

Examples: Given: Register 00H = 55H, register 01H = 02H, register 02H = 17H, and C = "0":

RRC

00H

Register 00H

=

2AH, C = "1"

RRC

@01H

Register 01H

=

02H, register 02H = 0BH, C = "1"

In the first example, if the general register 00H contains the value 55H (01010101B), the statement "RRC 00H" rotates this value one bit position to the right. The initial value of bit zero ("1") replaces the carry flag and the initial value of the C flag ("1") replaces bit 7. This leaves the new value 2AH (00101010B) in the destination register 00H. The sign flag and the overflow flag are both cleared to "0".

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Samsung S3C84E5 user manual RRC Rotate Right through Carry, RRCdst Operation dst 7 ← C, 00H Register 00H 2AH, C =