dsp56800e Freescale Semiconductor, Inc, dsp56800e Datasheet - Page 383

• Manufacturer Part Number: dsp56800e
• Description: 16-bit Digital Signal Controller Core
• Manufacturer: Freescale Semiconductor, Inc

ASL16
Operation:
S << 16 → D
Description: Arithmetically shift the source operand to the left by 16 bits, and store the result in the destination (D).
Example:
Explanation of Example:
Condition Codes Affected:
Instruction Fields:
Instruction Opcodes:
Timing:
Memory:
Freescale Semiconductor
ASL16 FFF,FFF
Operation
ASL16
Before Execution
A2
0
This operation effectively places the LSP of the source register into the MSP of the destination register.
The low-order 16 bits of the destination are always set to zero. Bits are shifted into the extension reg-
ister (FF2) if the destination is an accumulator. When the destination operand is a 16-bit register, the
LSP of an accumulator or Y register is written to it. When both the source and destination are 16-bit
registers, the destination is cleared. The result is not affected by the state of the saturation bit (SA).
ASL16
Prior to execution, the Y register contains the value to be shifted ($0000:7FFF). The contents of the
destination register are not important prior to execution because they have no effect on the calculated
value. The ASL16 instruction arithmetically shifts the value $0000:7FFF by 16 bits to the left and plac-
es the result in the destination register A.
The condition codes are not affected by this instruction.
1 oscillator clock cycle
1 program word
(no parallel move)
3456
0000
A1
Y1
Y,A
Operands
FFF,FFF
FFF
Arithmetic Shift Left 16 Bits
7FFF
3456
A0
Y0
15
0
Instruction Set Details
1
; shift Y left 16 bits, store in A
C
1
1
1
Assembler Syntax:
ASL16
W
1
1
12
1
Arithmetic shift left the first operand by 16 bits, placing
result in the destination operand
An alternate syntax for the preceding instruction if the
source and the destination are the same
11
1
After Execution
A2
0
1
F
S,D
7FFF
0000
F
8
A1
Y1
F
7
Comments
b
b
(no parallel move)
7FFF
0000
b
4
A0
Y0
ASL16
0
3
1
0
1
A-39
0