SEU Mitigation User Guide: Agilex™ 5 FPGAs and SoCs

ID 813649
Date 11/25/2024
Public
Document Table of Contents

2.4.1.4. Sensitivity Map Header Lookup

The .smh file represents a hash of the design's CRAM bit settings. The .smh file maps related groups of CRAM to a signal bit in the sensitivity array.

During an SEU, your application can look up the .smh file to determine if a bit is used. Using the bit location information, you can reduce the effective soft error rate in a running system.

The following criteria determine the criticality of a CRAM location in your design:

  • Routing—all bits that control a utilized routing line are considered sensitive.
  • Adaptive logic modules (ALMs)—if you configure an ALM, the Advanced SEU Detection IP considers all CRAM bits related to that ALM as sensitive.
  • Logic array block (LAB) control lines—if you use an ALM in a LAB, the Advanced SEU Detection IP considers all bits related to the control signals feeding that LAB as sensitive.
  • M20K memory and digital signal processing (DSP) blocks—if you use a block, the Advanced SEU Detection IP considers all CRAM bits related to that block as sensitive.