Arithmetic Logic Unit (Alu); Alu Operations - Analog Devices ADSP-BF53x Blackfin Reference

Arithmetic Logic Unit (ALU)

Arithmetic Logic Unit (ALU)
The two ALUs perform arithmetic and logical operations on fixed-point
data. ALU fixed-point instructions operate on 16-, 32-, and 40-bit
fixed-point operands and output 16-, 32-, or 40-bit fixed-point results.
ALU instructions include:
• Fixed-point addition and subtraction of registers
• Addition and subtraction of immediate values
• Accumulation and subtraction of multiplier results
• Logical AND, OR, NOT, XOR, bitwise XOR, Negate
• Functions: ABS, MAX, MIN, Round, division primitives

ALU Operations

Primary ALU operations occur on ALU0, while parallel operations occur
on ALU1, which performs a subset of ALU0 operations.
Table 2-8 describes the possible inputs and outputs of each ALU.
Table 2-8. Inputs and Outputs of Each ALU
Input
Two or four 16-bit operands
Two 32-bit operands
32-bit result from the multiplier
Combining operations in both ALUs can result in four 16-bit results, two
32-bit results, or two 40-bit results generated in a single instruction.
2-26 ADSP-BF53x/BF56x Blackfin Processor Programming Reference
Output
One or two 16-bit results
One 32-bit result
Combination of 32-bit result from the multiplier
with a 40-bit accumulation result