Rotate Right
ROR
13-207
Assembly Language Instructions
Syntax
ROR
dst
Operation
dst right-rotated one bit through carry bit
→
dst
Operands
dst register (Rn, 0
≤
n
≤
27)
Opcode
31
24 23
16
8 7
0
15
0 0 0
1 0
0
1
1
0
dst
1 1
1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1
Description
The contents of the
dst operand are right rotated one bit and loaded into the
dst register. The LSB is rotated into the carry (C) bit and also transferred into
the MSB.
Rotate right:
C
dst
Cycles
1
Status Bits
These condition flags are modified only if the destination register is R7– R0.
LUF
Unaffected
LV
Unaffected
UF
0
N
MSB of the output
Z
1 if a 0 output is generated; 0 otherwise
V
0
C
Set to the value of the bit rotated out of the high-order bit; unaffected
if
dst is not R7–R0
OVM
Operation is not affected by OVM bit value.
Example
ROR R7
Before Instruction
After Instruction
R7
00 0000 0421
R7
00 8000 0210
LUF
0
LUF
0
LV
0
LV
0
UF
0
UF
0
N
0
N
1
Z
0
Z
0
V
0
V
0
C
0
C
1
Mode Bit