Asrr, Multiple-bit arithmetic shift right (dalu), Description – Freescale Semiconductor StarCore SC140 User Manual

Page 374: Status and conditions that affect instruction, Operation assembler syntax

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SC140 DSP Core Reference Manual

ASRR

ASRR

Multiple-Bit Arithmetic Shift Right (DALU)

ASRR

Description

This operation shifts the contents of Dn by N bits. Bits shifted out of Dn are lost except for the last bit,
which is stored in the C bit.

Status and Conditions that Affect Instruction

None.

Operation

Assembler Syntax

Dn >> #u5

→ Dn

ASRR #u5,Dn {0

≤ u5 < 32}

If Da[6:0] > 0, then Dn >> Da[6:0]

→ Dn

else Dn << |Da[6:0]|

→ Dn

ASRR Da,Dn

ASRR #u5,Dn

Performs an arithmetic right shift by N, an immediate unsigned 5-bit integer. The MSB is copied into the
vacated positions.

ASRR Da,Dn

Performs a bidirectional arithmetic shift of Dn by Da[6:0] bits and stores the result in Dn. If Da[6:0] is
positive, the shift is right. If shifting right, the MSB is copied into the vacated positions. If shifting left, the
vacated positions to the right are zero-filled. N is obtained from Da[6:0].

0

15

16

31

32

39

C

0

0

15

16

31

32

39

C

0

15

16

31

32

39

C

Da[6:0]

> 0

Da[6:0]

< 0

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