dsp56800 Freescale Semiconductor, Inc, dsp56800 Datasheet - Page 377

• Manufacturer Part Number: dsp56800
• Description: 16-bit Digital Signal Controllers
• Manufacturer: Freescale Semiconductor, Inc

ROR
Operation:
(see figure)
:
Description: Logically shift 16 bits of the destination operand (D) 1 bit to the right, and store the result in the des-
Example:
Explanation of Example:
Condition Codes Affected:
Instruction Fields:
Timing:
Memory:
Freescale Semiconductor
Operation
ROR
Before Execution
B2
SR
F
tination. If the destination is a 36-bit accumulator, the result is stored in the MSP of the accumulator
(FF1 portion), and the remaining portions of the accumulator are not modified. The LSB of the desti-
nation (bit 16 for a 36-bit accumulator) prior to the execution of the instruction is shifted into C, and
the previous value of C is shifted into the MSB of the destination (bit 31 for a 36-bit accumulator). The
result is not affected by the state of the saturation bit (SA).
ROR
Prior to execution, the 36-bit B accumulator contains the value $F:0001:00AA. Execution of the
ROR B instruction shifts the 16-bit value in the B1 register 1 bit to the right, shifting bit 16 into C,
rotating C into bit 31, and storing the result back in the B1 register.
2 oscillator clock cycles
1 program word
15
LF
0001
0000
14
B1
*
N
Z
V
C
13
*
C
Operands
— Set if bit 31 of accumulator result or MSB of register is set
— Set if bits 31–16 of accumulator result or all bits of register are zero
— Always cleared
— Set if bit 16 of accumulator or bit 0 of register was set prior to the execution of the
FDD
B
12
*
MR
instruction
11
Unch.
*
00AA
D2
B0
10
*
Instruction Set Details
Rotate Right
I1
9
C
2
Assembler Syntax:
ROR
D1
I0
8
W
1
SZ
7
; rotate B1 right 1 bit
After Execution
Rotate 16-bit register right by 1 bit through the carry bit
6
L
B2
SR
F
Unchanged
5
E
D
D0
4
U
CCR
0000
0005
B1
N
3
Z
Comments
2
V
1
00AA
C
0
B0
ROR
A-147