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Lsl logical shift left lsl – Motorola DSP96002 User Manual

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MOTOROLA

DSP96002 USER’S MANUAL

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LSL

Logical Shift Left

LSL

Operation:

Assembler Syntax:

LSL D (move syntax - see the Move instruction description.)

LSL S,D (move syntax - see the Move instruction description.)

LSL #bits,D

Description:

Single-bit shift:

Logically shift the low portion of the specified operand one bit to the left. The carry bit receives the MSB

shifted out of the low portion of the source operand. A zero is shifted into the least significant bit of the

destination operand. The result is stored in the low portion of D.

Multi-bit shift:

Logically shift the low portion of the specified operand N bits (up to 63 bits) to the left. The number of bits

to shift is determined by the 11-bit unsigned integer located in the 11 LSBs of the high portion of S, or by

a a 6-bit immediate field in the instruction. The carry bit receives the Nth bit shifted out of the low portion

of the source operand; it is cleared for a shift count of zero. N zeros are shifted into the LSBs of the des-

tination operand. If more than 32 bits are shifted, zeros will be stored in D and the carry bit. The result is

stored in the low portion of D.

Input Operand(s) Precision: 32-bit integer.

Output Operand Precision: 32-bit integer.

CCR Condition Codes:

C

- Set if the last bit shifted out of the operand is set. Cleared otherwise. Cleared for a

shift count of zero.

V

- Always cleared.

Z

- Set if result is zero. Cleared otherwise.

N

- Set if result is negative. Cleared otherwise.

I

- Not affected.

LR

- Not affected.

R

- Not affected.

A

- Not affected.

ER Status Bits: Not affected.

IER Flags: Not affected.

31

0

C

0

(parallel data bus move)