ROR ACC
6-311
ROR ACC Rotate Accumulator Right
SYNTAX OPTIONS OPCODE OBJMODE RPT CYC
ROR ACC 1111 1111 0101 0010 X Y N+1
Operands ACC Accumulator register
Description Rotate the content of the ACC register right by one bit, filling bit 31 with the
content of the carry flag and loading the carry flag with the bit shifted out:
Rotate Right
C
ACC
ACC
Flags and
Modes
N After the operation, the N flag is set if bit 31 of the ACC is 1, else N is cleared.
Z After the operation, the Z flag is set if the ACC is zero, else Z is cleared.
C The value in bit 0 of the ACC register is transferred to C. The value in C
before the rotation is transferred to bit 31 of the ACC.
Repeat This instruction is repeatable. If the operation follows a RPT instruction, then
the ROR instruction will be executed N+1 times. The state of the Z, N, and C
flags will reflect the final result.
Example
; Rotate contents of VarA right by 5:
MOVL ACC,@VarA ; ACC = VarA
RPT #4 ; Repeat next instruction 5 times
||ROR ACC ; Rotate ACC right
MOVL @VarA,ACC ; Store result into VarA