DALU

Table 2-5. DALU Arithmetic Instructions (MAC) (Continued)

Instruction

Description

 

 

 

 

NEG

Negate

 

 

RND

Round

 

 

SAT.F

Saturate fractional value in data register to fit in high portion

 

 

SAT.L

Saturate value in data register to fit in 32 bits

 

 

SBC

Subtract long with carry

 

 

SBR

Subtract and round

 

 

SUB

Subtract

 

 

SUB2

Subtract two words

 

 

SUBL

Shift left and subtract

 

 

SUBNC.W

Subtract with no carry bit generation

 

 

TFR

Transfer data register to a data register

 

 

TFRF

Transfer data register to a data register if T bit is false

 

 

TFRT

Transfer data register to a data register if T bit is true

 

 

TSTEQ

Test for equal to zero

 

 

TSTEQ.L

32-bit compare for equal to zero

 

 

TSTGE

Test for greater than or equal to zero

 

 

TSTGT

Test for greater than zero

 

 

2.2.1.3 Bit-Field Unit (BFU)

The BFU is the logic part of the ALU. It contains a 40-bit parallel bidirectional shifter (with a 40-bit input and a 40-bit output) mask generation unit and logic unit. The BFU is used in the following operations:

Multi-bit left/right shift (arithmetic or logical)

One-bit rotate (right or left)

Bit-field insert and extract

Count leading bits (ones or zeros)

Logical operations

Sign or zero extension operations

Table 2-6 lists the instructions which are executed in the BFU. A more detailed description of each instruction is given in Appendix A, “SC140 DSP Core Instruction Set.”

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SC140 DSP Core Reference Manual

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Freescale Semiconductor SC140 specifications Neg