Programming Cyclone IV FPGA using USB Blaster Rev A

[Altera_Forum]

Hi, 

 I am testing a custom Cyclone IV board. I am using USB BLASTER Rev.A to program the FPGA via JTAG as well as AS modes. I am able to configure the EPCS64 configuration memory when USB Blaster cable is connected to AS mode header, however all attempts to use JTAG mode (using separate header) results in "JTAG chain broken" error by the programmer.   I am following Cyclone IV Device Handbook Volume -1 and programming setup is according to figure 8-28 "Combining JTAG and AS Configuration Schemes".   I am wondering if USB BLASTER Rev.A actually supports Cyclone IV FPGAs as I have seen people on the internet as well as in this forum using. Rev.C or USB Blaster II with Cyclone IV and above FPGAs.  The USB Blaster I am using is this one: http://www.terasic.com.tw/cgi-bin/page/archive.pl?language=english&categoryno=&no=46  Any Suggestions ?  regards

[Altera_Forum]

I have a rev B cable working quite happily with Cyclone IV and I'm (pretty) sure I used to have a rev A cable doing the same. The only difference between rev A & rev B is they changed from ribbon cable (on A) to a flexible PCB cable. 

 I also have a USB-Blaster rev B whose flexible cable broke. I replaced it with standard ribbon cable but ended up having to reduce it's length to get it working.  So, I can well imagine you having issues with your rev A cable. I suggest you try reducing the length if the ribbon cable. Mine ended up pretty short...  https://www.alteraforum.com/forum/attachment.php?attachmentid=11055   ...much shorter than necessary.  Cheers, Alex

[Altera_Forum]

I've used the Terasic USB Blaster with a Cyclone IV (JTAG) without any problems.