Symmetric Cryptographic Accelerator Hard IP User Guide

Download PDF
ID 714305
Date 11/28/2025
Public
Document Table of Contents
Document Table of Contents x
1. Introduction 2. Interface Overview 3. Parameters 4. Designing with the IP 5. Block Description 6. Cryptographic IP Data Profiles 7. Configuration Registers 8. Design Example 9. Document Revision History for the Symmetric Cryptographic Accelerator Hard IP User Guide
1. Introduction x
1.1. Terminology 1.2. IP Overview 1.3. Release Information 1.4. Device Family Support 1.5. Resource Utilization
1.2. IP Overview x
1.2.1. IP Applications
2. Interface Overview x
2.1. Clock Signals 2.2. Reset Signals 2.3. AXI-ST Interface 2.4. AXI-Lite Interface
4. Designing with the IP x
4.1. Installing and Licensing IP Cores 4.2. Specifying the IP Parameters and Options 4.3. Generated File Structure 4.4. Symmetric Cryptographic Accelerator Hard IP Flow 4.5. Dynamically Disabling the SM4 Capability 4.6. Error Handling 4.7. Error Reporting 4.8. Resetting the IP 4.9. Channel Definition and Allocation 4.10. Byte Ordering 4.11. AXI-ST Single Packet Mode 4.12. AXI-ST Multiple Packet Mode
4.1. Installing and Licensing IP Cores x
4.1.1. IP Evaluation Mode
4.6. Error Handling x
4.6.1. Steps to Record and Report the Received Errors to the Soft Logic 4.6.2. Detected Error Handling 4.6.3. Key RAM ECC Error Handling
4.6.2. Detected Error Handling x
4.6.2.1. Recovering from a Recoverable Error 4.6.2.2. Recovering from an Internal Error
5. Block Description x
5.1. Reset Sequencer 5.2. AXI-ST Ready Latency 5.3. AXI Adapter 5.4. Integrity Check Value Comparison 5.5. GCM Padding and Depadding
5.3. AXI Adapter x
5.3.1. MAC Packing 5.3.2. Data Last Indicator 5.3.3. Stream and Channel ID Buffering 5.3.4. TKEEP and LAST_SEGMENT Signals Generation 5.3.5. MAC Dropping on Decryption
5.5. GCM Padding and Depadding x
5.5.1. GCM Padding 5.5.2. GCM Depadding
6. Cryptographic IP Data Profiles x
6.1. MAC Security Profile (MACsec) 6.2. IP Security Profile (IPsec) 6.3. Generic GCM Profile (GCM) 6.4. Generic XTS Profile (XTS)
6.1. MAC Security Profile (MACsec) x
6.1.1. MACsec Flow 6.1.2. AXI-ST Interface Using MAC Security (MACsec) Profile Pattern
6.2. IP Security Profile (IPsec) x
6.2.1. AXI-ST Interface Using IP Security (IPsec) Profile Pattern
6.3. Generic GCM Profile (GCM) x
6.3.1. AXI- ST Interface Using Generic GCM Profile Pattern
6.4. Generic XTS Profile (XTS) x
6.4.1. AXI-ST Interface Using Generic XTS Profile Pattern
8. Design Example x
8.1. Functional Description 8.2. Crypto VSIP Top Block Descriptions 8.3. Test Configurations 8.4. Software Requirements 8.5. Simulation Requirements 8.6. Steps to Generate the Design Example 8.7. Running Simulation Tests 8.8. Running Hardware Tests
8.2. Crypto VSIP Top Block Descriptions x
8.2.1. Clock and Reset 8.2.2. Host Interface
8.7. Running Simulation Tests x
8.7.1. Steps to Simulate the Design Example
8.8. Running Hardware Tests x
8.8.1. Supported Boards 8.8.2. Steps to Compile the Design Example for Hardware 8.8.3. Steps to Run the Design Example on Hardware
1. Introduction
2. Interface Overview
3. Parameters
4. Designing with the IP
5. Block Description
6. Cryptographic IP Data Profiles
7. Configuration Registers
8. Design Example
9. Document Revision History for the Symmetric Cryptographic Accelerator Hard IP User Guide

5.5.2. GCM Depadding

This block implements the idle byte depadding to the AAD, Bypass, Text, and MAC fields, which are 16 bytes aligned if you turn on Enable Gen. GCM egress depadding in the IP parameter editor. You must send in the real AAD and Bypass field lengths, regardless of whether the GCM padding on ingress is enabled or disabled. If the GCM padding on ingress is disabled, the AAD and Bypass fields are 16 byte-aligned, and the IP routes the real AAD and Bypass lengths to Crypto egress logic for depadding.

The egress decryption MAC is dropped if you also turn on Drop the MAC on applicable profile decryption in the IP parameter editor.

If you do not turn on Enable Gen. GCM egress depaddingin the IP parameter editor, the depadding logic within the IP is optimized away to save device resources. In this case, the egress data still passes through the ICV and MAC packing blocks.
Figure 16. GCM Depadding
Note: The MAC(16B) in the dash-line box indicates that the MAC is removed from the decryption packets if you turn on Drop the MAC on applicable profile decryptionin the IP parameter editor.
Level Two Title