Symmetric Cryptographic Accelerator Hard IP User Guide

ID 714305
Date 11/28/2025
Public
Document Table of Contents

5.5.1. GCM Padding

This block implements the idle bytes padding to the AAD and Bypass fields, which are not 16 byte-aligned if you turn on Enable Gen. GCM AAD-Bypass ingress padding in the IP parameter editor. You must send in the real AAD and Bypass fields length.

If you do not turn on Enable Gen. GCM AAD-Bypass ingress padding in the IP parameter editor, the padding logic within the IP is optimized away to save device resources.
Figure 15. GCM Padding