ASLA

ASLA

Arithmetic Shift Left

 

By One Bit (AGU)

Operation

Assembler Syntax

Rx<<1 → Rx

ASLA Rx

ASLA

Description

ASLA Rx

Shifts an AGU (Rx) register left one bit. Bits [30:0] are copied into bits [31:1]. Bit 0 is cleared.

Status and Conditions that Affect Instruction

Register Address

Bit Name

Description

SR[18]

EXP

Determines which stack pointer is used when the stack pointer is an

 

 

operand. Otherwise, the instruction is not affected by SR.

Status and Conditions Changed by Instruction

None.

Example

asla r0

Register/Memory Address

R0

Before

$e001 0002

After

$c002 0004

Instruction Formats and Opcodes

Instruction

Words

Cycles

Type

ASLA Rx

1

1

2

Opcode

158 70

1 1 1 0 R R R R 1 1 1 1 1 1 0 0

Instruction Fields

Rx

RRRR

 

AGU Source/Destination Register

 

 

 

0000

N0

0100

1000

R0

1100

R4

 

 

 

 

 

 

 

 

 

 

0001

N1

0101

1001

R1

1101

R5

 

 

 

 

 

 

 

 

 

 

0010

N2

0110

1010

R2

1110

R6

 

 

 

 

 

 

 

 

 

 

0011

N3

0111

SP

1011

R3

1111

R7

 

 

 

 

 

 

 

 

Note:

This instruction

can specify R8-R15 as operands by using a high register prefix.

 

SC140 DSP Core Reference Manual

A-51

Page 365
Image 365
Freescale Semiconductor SC140 specifications Asla r0, Rx1 → Rx, Asla Rx