Nios II Classic Processor Reference Guide

ID 683620
Date 10/28/2016
Public
Document Table of Contents

8.5.6. beq

Instruction branch if equal
Operation

if (rA == rB)

then PC ←  PC + 4 + σ(IMM16)

else PC ←  PC + 4

Assembler Syntax

beq rA, rB, label

Example

beq r6, r7, label

Description

If rA == rB, then beq transfers program control to the instruction at label. In the instruction encoding, the offset given by IMM16 is treated as a signed number of bytes relative to the instruction immediately following beq. The two least-significant bits of IMM16 are always zero, because instruction addresses must be word-aligned.

Exceptions

Misaligned destination address

Instruction Type

I

Instruction Fields

A = Register index of operand rA

B = Register index of operand rB

IMM16 = 16-bit signed immediate value

Bit Fields
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16
A B IMM16
15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
IMM16 0x26