Forum Discussion

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

JTAG error only when programming

Hello, I have a custom board with a MAXII CPLD (EPM2210F256), with the JTAG port built per the Handbook. With Quartus-II v. 9.1 and a ByteblasterMV cable I can ID the device, erase it, and bla...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
14 years ago

--- Quote Start ---

I put an oscilloscope on the (4) JTAG signals and the power supply- all look very clean.

--- Quote End ---

What bandwidth is your scope? A low bandwidth ~50MHz scope might not show ringing and steps in the TCK signal due to transmission line reflections.

--- Quote Start ---

Can anyone shed any light on this or suggest other ideas to check?

--- Quote End ---

Try another ByteBlaster, or better yet, try a USB-Blaster. If you don't have one, Terasic sells them for $50. They work well.

Cheers,

Dave