dsp56800 Freescale Semiconductor, Inc, dsp56800 Datasheet - Page 376

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

ROL
Operation:
(see figure)
Description: Logically shift 16 bits of the destination operand (D) 1 bit to the left, and store the result in the desti-
Example:
Explanation of Example:
Condition Codes Affected:
Instruction Fields:
Timing:
Memory:
A-146
Operation
ROL
Before Execution
B2
SR
F
nation. 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 MSB of the desti-
nation (bit 31 for accumulators or bit 15 for registers) prior to the execution of the instruction is shifted
into C, and the previous value of C is shifted into the LSB of the destination (bit 16 if the destination
is a 36-bit accumulator). The result is not affected by the state of the saturation bit (SA).
ROL
Prior to execution, the 36-bit B accumulator contains the value $F:0001:00AA. Execution of the
ROL B instruction shifts the 16-bit value in the B1 register 1 bit to the left, shifting bit 31 into C, ro-
tating C into bit 16, and storing the result back in the B1 register.
2 oscillator clock cycles
1 program word
15
LF
0000
0001
14
B1
*
N
Z
V
C
13
C
*
Operands
— Set if bit 31 of accumulator result or bit 15 of register result is set
— Set if bits 31–16 of accumulator result or all bits in register result are zero
— Always cleared
— Set if bit 31 of accumulator or bit 15 or register result was set prior to the execution
FDD
B
12
*
MR
of the instruction
Unch.
11
*
D2
00AA
B0
DSP56800 Family Manual
10
*
Rotate Left
I1
9
C
2
D1
Assembler Syntax:
ROL
I0
8
W
1
SZ
7
After Execution
Rotate 16-bit register left by 1 bit through the carry bit
6
L
B2
SR
F
Unchanged
5
E
D0
D
; rotate B1 left 1 bit
4
U
CCR
0001
0000
B1
N
3
Z
Comments
2
V
1
Freescale Semiconductor
00AA
C
0
B0
ROL