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SC140 DSP Core Reference Manual
DALU
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.”
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
Table 2-5. DALU Arithmetic Instructions (MAC) (Continued)
Instruction
Description
Summary of Contents for SC140 DSP Core
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