Exception Handling Verification

Concept

Exception handling verification is the part of constrained-random microprocessor verification that plans, generates, and controls exception-causing conditions so the design under test can be checked for exception detection, priority, and handling behavior. In the cited methodology, this includes early stimulus planning for specific exception causes and their probabilities, support in the opcode/operation model for illegal instructions, and selectively enabled or disabled constraints to generate cases such as misaligned memory accesses or illegal slot placement of operations.

First seen 6/1/2026

Last seen 6/1/2026

Evidence 3 chunks

Wiki v1

WIKI

Overview

Exception handling verification is treated as an explicit part of constrained-random microprocessor verification rather than as an accidental by-product of random instruction generation. The cited methodology says exception conditions must be planned early, because the verification model must cover both individual exception causes and their occurrence probabilities, and it should also generate multiple exception conditions at the same time to test exception priority and handling.

Why it is needed

READ FULL ARTICLE →

NEIGHBORHOOD

No graph connections found for this entity yet. It may appear in future ingestion runs.

explore full graph →

RELATIONSHIPS

2 connections

Microprocessor Verification part of → 93% 2e

Exception handling verification is a required part of processor verification.

opcode class ← implements 88% 1e

The opcode class supports illegal opcode generation for exception testing.

LINKED ENTITIES

2 links

Microprocessor Verification PART_OF Extracted graph relationship

opcode class IMPLEMENTS Extracted graph relationship

CITATIONS

8 sources

8 citations — click to expand

[1] Exception conditions must be planned early, covering specific causes, occurrence probability, and simultaneous exceptions to test exception priority and handling. Applying Constrained-Random Verification to Microprocessors

[2] Pure random instructions rarely create useful stimulus for important processor behaviors such as exceptions, so constrained-random infrastructure with ISA/state knowledge is needed. Applying Constrained-Random Verification to Microprocessors

[3] Program traces can include an exception handler and can introduce exception conditions randomly inside instruction scenarios. Applying Constrained-Random Verification to Microprocessors

[4] The operation/opcode class supports exception testing by adding an ILLEGAL kind that uses a random unassigned opcode value to create an illegal instruction. Applying Constrained-Random Verification to Microprocessors

[5] Constraint rules can model exception-producing conditions, including load/store not in slot 0 and ERET not in slot 0. Applying Constrained-Random Verification to Microprocessors

[6] Constraint blocks are independently controllable; disabling the slot-0 rule can randomize load/store operations into slot 1 and cause an exception. Applying Constrained-Random Verification to Microprocessors

[7] Misaligned load/store accesses trigger an exception, and alignment constraints can be turned off in the scenario base class to inject such cases randomly. Applying Constrained-Random Verification to Microprocessors

[8] Some modeled rule violations are explicitly described as undefined behavior rather than exceptions, including ERET pairing and dual writes to the same scalar register in one instruction. Applying Constrained-Random Verification to Microprocessors