Arria® 10 Core Fabric and General Purpose I/Os Handbook

ID 683461
Date 7/08/2024
Document Table of Contents Initialization

The initialization clock source is from the internal oscillator, CLKUSR pin, or DCLK pin. By default, the internal oscillator is the clock source for initialization. If you use the internal oscillator, the Arria® 10 device provides enough clock cycles for proper initialization.

Note: If you use the optional CLKUSR pin as the initialization clock source and the nCONFIG pin is pulled low to restart configuration during device initialization, ensure that the CLKUSR or DCLK pin continues toggling until the nSTATUS pin goes low and then goes high again.

The CLKUSR pin provides you with the flexibility to synchronize initialization of multiple devices or to delay initialization. Supplying a clock on the CLKUSR pin during initialization does not affect configuration. After the CONF_DONE pin goes high, the CLKUSR or DCLK pin is enabled after the time specified by tCD2CU . When this time period elapses, Arria® 10 devices require a minimum number of clock cycles as specified by Tinit to initialize properly and enter user mode as specified by the tCD2UMC parameter.