DALU

 

Table 2-6. DALU Logical Instructions (BFU)

 

 

 

Instruction

 

Description

 

 

 

 

 

 

AND

 

Logical AND

 

 

 

ASLL

 

Multi-bit arithmetic shift left

 

 

 

ASLW

 

Word arithmetic shift left (16-bit shift)

 

 

 

ASRR

 

Multi-bit arithmetic shift right

 

 

 

ASRW

 

Word arithmetic shift right (16-bit shift)

 

 

 

CLB

 

Count leading bits (ones or zeros)

 

 

 

EOR

 

Bit-wise exclusive OR

 

 

 

EXTRACT

 

Extract signed bit-field

 

 

 

EXTRACTU

 

Extract unsigned bit-field

 

 

 

INSERT

 

Insert bit-field

 

 

 

LSLL

 

Multi-bit logical shift left

 

 

 

LSR

 

Logical shift right by one bit

 

 

 

LSRR

 

Multi-bit logical shift right

 

 

 

LSRW

 

Word logical shift right (16-bit shift)

 

 

 

NOT

 

One’s complement (inversion)

 

 

 

OR

 

Bit-wise inclusive OR

 

 

 

ROL

 

Rotate one bit left through the carry bit

 

 

 

ROR

 

Rotate one bit right through the carry bit

 

 

 

SXT.B

 

Sign extend byte

 

 

 

SXT.L

 

Sign extend long

 

 

 

SXT.W

 

Sign extend word

 

 

 

ZXT.B

 

Zero extend byte

 

 

 

ZXT.L

 

Zero extend long

 

 

 

ZXT.W

 

Zero extend word

 

 

 

2.2.1.4 Data Shifter/Limiter

The data shifters/limiters provide special post-processing on data written from a Dn register to the XDBA or XDBB buses. There are eight independent shifters/limiters, four for the XDBA bus and four for the XDBB bus, allowing transfers to memory of up to four words per MOVES instruction with scaling and limiting. Each consists of a shifter for scaling followed by a limiter. Note that arithmetic saturation from DALU operations is a different function. Saturation occurs in the DALU before data is written to a destination register.

SC140 DSP Core Reference Manual

2-13

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Image 45
Freescale Semiconductor SC140 specifications Data Shifter/Limiter, Dalu Logical Instructions BFU