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Lsra, Bitwise shift right by one bit (agu), Example – Freescale Semiconductor StarCore SC140 User Manual

Page 541: Instruction formats and opcodes instruction fields, Operation assembler syntax, Lsra r2

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LSRA

SC140 DSP Core Reference Manual

A-227

LSRA

Bitwise Shift Right By One Bit (AGU)

LSRA

Description

Status and Conditions that Affect Instruction

Status and Conditions Changed by Instruction

None.

Example

lsra r2

Instruction Formats and Opcodes

Instruction Fields

Rx

RRRR

AGU Source/Destination Register

Operation

Assembler Syntax

(Rx>>>1)

→ Rx; 0 → Rx[31]

LSRA Rx

LSRA Rx

Shifts the contents of an AGU register (Rx) right one bit. Bits [31:1] are copied to bits [30:0]. Bit 31 is
cleared.

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.

Register/Memory Address

Before

After

R2

$AAAA AAAA

$5555 5555

Instruction

Words Cycles Type

Opcode

15

8

7

0

LSRA Rx

1

1

2

1

1

1

0

R R R R

1

1

1

1

1

1

1

1

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.