Nios® V Processor Reference Manual

ID 683632
Date 11/15/2021

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2.3.2. Arithmetic Logic Unit

The Arithmetic Logic Unit (ALU) operates on data stored in general-purpose registers. ALU operations take one or two inputs from registers and store the result back into the register. The ALU supports four fundamental data operations described in the following table.

Table 5.  Supported Operations
Category Description
Arithmetic The ALU supports addition and subtraction on signed and unsigned operands.
Relational The ALU supports the equal, not-equal, greater-than-or-equal, and less-than relational operations (==, != >=, <) .
Logical The ALU supports AND, OR, NOR, and XOR logical operations.
Shift The ALU supports logical and arithmetic shift operations.

For load/store instructions, Nios® V/m processor uses ALU to calculate the memory address. For conditional control transfer instructions, Nios® V/m processor uses the relational operations in ALU area to decide whether to take the branch or not.