Category: Specifications
Tools: Quartus® Prime / Quartus II
Device: Cyclone® V


The HPS_CLK1 and HPS_CLK2 pins are dedicated clock inputs for the Hard Process System (HPS).
The HPS_CLK1 pin is used as the CPU core clock, so it must be a clock input.

If the clock can be input to the HPS_CLK1 pin, there is no problem whether or not to input the clock to the HPS_CLK2 pin.

Please also refer to the following documents.
https://www.altera.com/en_US/pdfs/literature/hb/cyclone-v/cv_5v4.pdf
(Search by keyword in Clock Manager Block Diagram.)