Status Pin Handling - Status Pin Handling - UG860

Spartan UltraScale+ FPGAs Configuration User Guide (UG860)

Document_ID
UG860
Release_Date
2026-07-27
Revision
v1.3 English

There are physical status pins that are recommended to be accessible on the board for debug. The two most important pins are the INIT_B and the DONE. INIT_B rising from Low to High indicates the completion of initialization after power-up, and then the falling INIT_B signal later in the process can indicate a CRC error. DONE indicates a successful configuration of the device. In addition to the status signals there are key configuration pins that provide helpful information and should be handled carefully to prevent problems during configuration. These pins include: