AN 796: Cyclone® V and Arria® V SoC Device Design Guidelines

ID 683360
Date 3/30/2022
Document Table of Contents Boot Clock

GUIDELINE: Determine boot clock source.

The boot clock influences the boot duration. Consider your system boot speed requirement as the primary factor in choosing the book clock. The system boot time requirement depends on how fast the FPGA needs to be configured for an appropriate response time, and how quickly the HPS software must be booted. The HPS software boot speed is influenced by the following factors:
  • Value of external clock to the HPS (i.e. OSC1 clock)
  • Boot flash source interface operation frequency
Boot clock configurations are selected with the CSEL pins. Available combinations are described in the appropriate Hard Processor System Technical Reference Manual.
Note: CSEL pins are not used when booting from FPGA fabric.