JTAG supply voltage and USB blaster 2/EPCQ-1

aakkü · ‎03-31-2019

Hello,

I am trying to implement JTAG connection with PCB. I intent to use USB blaster to program the FPGA. In the handbook (cyclone 10 LP) it says "For device using VCCIO of 2.5, 3.0, and 3.3 V, all I/O inputs must maintain a maximum AC voltage of 4.1 V because JTAG pins do not have the internal PCI clamping diodes to prevent voltage overshoot. You must power up the VCC of the download cable with a 2.5-V supply from VCCA"

I think it basically says the pull-up resistors should be powered with 2.5V. However, in EK-10CL025U256 board it uses 3.3V. What am I missing here? Can you please clarify which voltage supply level should I use for the JTAG section and do I have to apply voltage to the VCC(TRGT) pin in the usb blaster connector?

I also want to program the PROM device connected to the FPGA via JTAG. The serial configuration device that I am using is EPCQ32A. It's not listed in the USB blaster datasheet. Can I still use it store the configuration data.

Thank!

ShafiqY_Intel · ‎05-14-2019

Hi aakku,

If you refer to the Cyclone 10 LP pin guideline, JTAG pins need to connect it to VCCA which is 2.5V. otherwise, I'm not guarantee it will work.

Yes, EPCQ-A device can use to store configuration data.

Thanks

aakkü · ‎05-14-2019

Thank you!

Some development boards' datasheet show 3.3V connected to JTAG for some reason. That's why U wanted to make sure.

Thanks for confirming that.