JTAG error only when programming

[Altera_Forum]

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 blank-check it with no problem.   Only when I try to program it do I get the error: "can't access JTAG chain." I put an oscilloscope on the (4) JTAG signals and the power supply- all look very clean.   The data book says "Failures during in-system programming may occasionally be related to the Quartus II software" and says to look on the web site for details. I haven't found any there.   Can anyone shed any light on this or suggest other ideas to check?   Much appreciated...

[Altera_Forum]

--- 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

[Altera_Forum]

Dave, thanks for your reply. My scope is 200MHz BW, 1Gsa/sec. If there are any glitches they are <10nsec wide and die out very fast. 

 Probably I will try the Terasic programmer (note Atlera lists their USB-Blaster for $300!). Also in proces of downloading the latest Quartus SW, so we'll see...   Thanks again.

[Altera_Forum]

--- Quote Start ---  My scope is 200MHz BW, 1Gsa/sec. If there are any glitches they are <10nsec wide and die out very fast.    --- Quote End ---    Ok, the scope sounds good enough. The fact that you do not see any glitches is a good sign.    --- Quote Start ---   Probably I will try the Terasic programmer (note Atlera lists their USB-Blaster for $300!). Also in proces of downloading the latest Quartus SW, so we'll see...    --- Quote End ---    Yeah, the Altera versions are way too pricey. The Terasic versions work great!  Cheers, Dave