AN 763: Intel® Arria® 10 SoC Device Design Guidelines

ID 683192
Date 5/17/2022
Public
Document Table of Contents

5.1.10.1.5. Determine Boot Fuses Usage

GUIDELINE: If possible, defer blowing fuses to the end of development, to allow more flexibility for debugging purposes. Once the fuses are blown, they cannot be returned to their original values. While in the development stage of the design, you may experiment with modifying CSEL values without having to permanently program the CSEL fuse bits, by using HPS_FUSESEC shadow registers as a proxy for CSEL fuse bits. In order to revert device to its default behavior simply power cycle the device.

GUIDELINE: Determine how boot fuses are to be configured.

Different fuses are available, and they can influence the boot flow. For example, if the boot from FPGA fuse is blown, the BSEL pins are not used to determine the boot source and the HPS boots exclusively from the FPGA fabric. This protocol can be useful in some security scenarios.

Refer to the Arria 10 HPS Technical Reference Manual for a complete list of fuses and their behavior and to determine in advance how they must be set for the project.