Agilex™ 5 ES Device Errata and User Guidelines

ID 825514
Date 12/09/2024
Public
Document Table of Contents

3.1.8. 1214720: VFP_SPEC PMU event might count incorrectly

Description

The Cortex-A55 core implements several architectural and IMPLEMENTATION DEFINED performance monitor events. Because of this erratum, the VFP_SPEC event might not count correctly.

Conditions

One of the PMU event counters is configured to count the 0x075, VFP_SPEC event.

Impact

The PMU counts SIMD floating-point instructions as well as scalar floating-point instructions.

Workaround

In some situations, where integer SIMD instructions are known not to be used, the ASE_SPEC count can be subtracted from the VFP_SPEC count to give the number of scalar VFP instructions.

Category

Category C