user manual

INSTRUCTION DESCRIPTIONS

A - 262 INSTRUCTION SET DETAILS

MOTOROLA

Assembler Syntax:

ROL D (parallel move)

Description:

Rotate bits 47–24 of the destination operand D one bit to the left and store

the result in the destination accumulator. Prior to instruction execution, bit 47 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 24 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:

ROL A1 #314,N2 ;rotate A1 one left bit, update N2

Explanation of Example:

Prior to execution, the 56-bit A accumulator contains the

value $00:000000:000000. The execution of the ROL A instruction shifts the 24-bit value

in the A1 register one bit to the left, shifting bit 47 into the carry bit C, rotating the carry bit

C into bit 24, and storing the result back in the A1 register.

ROL Rotate Left ROL

47 24

(parallel move)

Operation:

Before Execution After Execution

A A

$00:000000:000000

SR SR

$0301

$0300

$00:000001:000000