Customizing the SDE module for FPGA/Host Interface

The CL_SDE (Custom Logic Streaming Data Engine) example in AWS F2 instances demonstrates how to handle data flows between the host and FPGA. Currently, the SDE module supports both Host-to-Card (H2C) and Card-to-Host (C2H) data flows.

For customizing the SDE module, you have a few options:

1. The CL_SDE example block diagram shows that data received from the host is forwarded to the H2C AXIS interface on SDE, where it's either looped back to SDE via the C2C AXIS interface or stored locally in the H2C Packet RAM within CL_SDE_SRM.

2. You can customize the SDE by either:

• Creating an interface to access the data in packet RAM
• For better performance, attaching the H2C AXIS interface directly to your packet processing logic

Both approaches would require Custom Logic (CL) design updates. The SDE offers data transfer capabilities comparable to the XDMA engine, allowing you to build a design with a performant mechanism for transferring data between the host and FPGA.

While there aren't ready-made software examples specifically demonstrating the H2C data flow for storing packets in FPGA memory, you can use the existing DPDK testpmd example as a starting point. The AWS team has mentioned they plan to release software examples for CL_SDE that will demonstrate how to handle data flows in both H2C and C2H directions.

If you're looking to integrate the SDE with memory like DDR4 or HBM, you would need to extend the design to connect to either memory type. The SDE itself functions as a DMA engine and works off the AXI bus that connects from the PCIe IP to the shell interface.

When working with the SDE, ensure that bus mastering is enabled, as this is required for proper operation. You can check and enable bus mastering using the commands provided in the SDE_LIB examples documentation.
Sources
CL_SDE example H2C software | AWS re:Post
After load cl_sde AFI, error (error_number=12) | AWS re:Post
Inquiry About Vitis AFI Generation Support on f2/vitis Branch | AWS re:Post