Hard Processor System Booting User Guide: Agilex™ 5 SoCs

ID 813762
Date 12/20/2024
Public
Document Table of Contents

4.11. Preserving SDRAM Content across HPS Resets for Agilex™ 5 Devices

The Agilex™ 5 device preserves SDRAM content during both cold and warm resets, regardless of the reset source. The IO96B DDR controller, which this device supports, enables this feature by continuing to run across these resets.

After an HPS reboot from a warm or cold reset, the HPS software evaluates certain conditions to determine if a full DDR initialization is necessary. If a full initialization is required, the SDRAM data is not preserved. During this process, a memory Built-in Self Test (BIST) is performed, resulting in the loss of data stored in SDRAM before the reset.