Forum Discussion
Altera_Forum
Honored Contributor
15 years agoYou should try to put a scope on the jtag signal to check what they look like.
Check also that the exposed pad is well connected to ground. While I don't see anything really wrong with your schematic, it is dangerous to directly connect the USB blaster to the Cyclone III at 3.3V without any protection. The probability of destroying the JTAG part of the FPGA with overshoots can be quite high, especially since the FPGA doesn't have any clamping diodes on the FPGA pins.