Motorola 24-Bit Digital Signal Processor, DSP56000 manual Rotate Right

INSTRUCTION DESCRIPTIONS

ROR

Rotate Right

ROR

Operation:

4724

C

(parallel move)

Assembler Syntax: ROR D (parallel move)

Description: Rotate bits 47–24 of the destination operand D one bit to the right and store the result in the destination accumulator. Prior to instruction execution, bit 24 of D is shifted into the carry bit C, and, prior to instruction execution, the value in the carry bit C is shifted into bit 47 of the destination accumulator D. This instruction is a 24-bit opera- tion. The remaining bits of the destination operand D are not affected.

Example:

:

ROR B1#$1234,R2 ;rotate B1 right one bit, update R2

:

B

Before Execution

$00:000001:222222

B

After Execution

$00:000000:222222

SR

$0300

SR

$0305

Explanation of Example: Prior to execution, the 56-bit B accumulator contains the value $00:000001:222222. The execution of the ROR B instruction shifts the 24-bit value in the B1 register one bit to the right, shifting bit 24 into the carry bit C, rotating the carry bit C into bit 47, and storing the result back in the B1 register.

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