Forum Discussion

Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
18 years ago

Cyclone II and NIOS frustrations

I have an EP2C20 on a new board that I'm trying to debug, and am having very strange problems. I am using a USB Blaster. Initially, the Quartus programmer would download the configuration, but...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
18 years ago

Hello,

the good thing with the JTAG problems is, that they depend on JTAG hardware only(assuming your power supply is O.K.), would be more difficult with design not operating correct after configuaration. Altera has apparently experimented a lot with driver hardware of USBBlaster, I think that AS programming is even worse than JTAG. With my revision B USBBlaster, I have been once increasing the TCK series resistor, also customer did that on Altera recommendation. Furthermore the flexprint adapter turned out to have unreliable contact with my exemplar, I changed it to a standard IDC cable and had no problems since that.

Customer hardware usually has additional transient suppression by schottky diodes and series resistor, this may also help against ringing TCK. The suggested 10 pF parallel capacitor at TCK could be useful instead.

Regards,

Frank