Agilex™ 7 Hard Processor System Technical Reference Manual

ID 683567
Date 8/13/2024
Public
Document Table of Contents

13.1.1.1. FPGA Boot First

If the FPGA First configuration has been selected, and after a Power-On-Reset (POR), then the SDM drives the HPS_COLD_nRESET signal to output low. At this point, referring to the Agilex™ 7 Configuration User Guide, the bitstream configuration file containing the FSBL must be resent to the SDM using the same interface that the MSEL[2:0] pins specified during POR. After the bitstream has been received, and after the FPGA is in User Mode, the SDM releases the HPS from reset, and the HPS_COLD_nRESET signal is configured as an input and can be pulled high by the external pull-up resister. The following figures show the FPGA boot first behavior.

Figure 35.  HPS_COLD_nRESET signal behavior (FPGA First, POR assert)

If the FPGA First configuration has been selected, and after nCONFIG has been asserted, then the SDM drives the HPS_COLD_nRESET signal to output low. After the bitstream has been received, and after the FPGA is in User Mode, the SDM releases the HPS from reset, and the HPS_COLD_nRESET signal is configured as an input and can be pulled high by the external pull-up resistor.

Figure 36.  HPS_COLD_nRESET signal behavior (FPGA First, nCONFIG assert)