No JTAG after AS programming on EP2C5T144

[Altera_Forum]

I tried just a hello world example on EP2C5T144 on a simple dev board. Programming via JTAG worked. I switched to AS and programmed it - all worked.  

 However, when I switch back to JTAG now, it doesn't work. When debugging JTAG, it says Incorrect clock and TDI value. AS programming still works.   Did I miss something obvious?

[Altera_Forum]

Hi, 

 1.which development kit you are using Starter Board or Mini Dev? 2.Have connected USB blaster to jtag header? 3.Try to load some other sof file and check or erase the flash and check Attach the error message and status of TMS, TCK, TDI & TDO.  Best Regards, Anand Raj Shankar (This message was posted on behalf of Intel Corporation)

[Altera_Forum]

Hi Anand, 

 Thanks for your reply. Erasing the flash helped. BTW, it's the Mini Dev and the blaster was connected correctly (I checked it about 20 times).  Is that expected behaviour that after programming the flash JTAG may not work? I used only board built in LEDs and button (pins 3,7,9, and 144).  Thanks

[Altera_Forum]

Hi, 

   --- Quote Start ---   Is that expected behaviour that after programming the flash JTAG may not work?    --- Quote End ---   No,this not expected behavior. This may be because of configuration file or signal integrity related issues. You can try to monitoring the flash and jtag signals which will help to find the exact cause of the problem.  Let me know if this has helped resolve the issue you are facing or if you need any further assistance.  Best Regards, Anand Raj Shankar (This message was posted on behalf of Intel Corporation)