Agilex™ 5 ES Device Errata and User Guidelines

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

3.2.18. 2263697: L1 Data poison is not cleared by a store

Description

The L1 Data poison is not cleared by a store under certain conditions.

Conditions

  1. A Processing Element (PE) executes a store that does not write a full word to a location that has data marked as poison.
  2. The PE executes another store that writes to all bytes that contain data poison before the previous store is globally observable.

Impact

If the above conditions are met, then the poison bit in the L1 Data cache does not get cleared.

Workaround

This erratum can be avoided by inserting a DMB before and after a word-aligned store that is intended to clear the poison bit.

Category

Category C