Why are unknown devices detected when Auto Detect is conducted for a single Intel® Stratix® 10 in the JTAG chain?

Description

Signal integrity problems on configuration signals at power-up may make a device to enter into an unexpected mode.

Unknown devices (for example, UNKNOWN_xxxx (xxxx is a number), UNKNOWN_NO_JTAG_ID) may be detected on the JTAG chain when Auto Detect is conducted by Programmer.

 

 

Resolution

Check and improve signal integrity of configuration signals(NCONFIG, NSTATUS) to help fix the problem.