Virtex II Pro and 3rd party devices in one JTAG chain?

Question

Does anyone know if it is OK to have 3rd party devices in one JTAG chainwith Xilinx FPGAs and CPLDs? The Xilinx devices I am using are XC2VP4 andXC9572XL...Thanks,/Mikhail-- To reply directly:matusov at square peg ca(join the domain name in one word and add a dot before "ca")

Symon · Accepted Answer

Mikhail,If you mean can you still program the FPGAs over the JTAG then yes, it's OK.I've done it before with a Virtex II and an Intel StrongArm processor. IIRCyou need a boundary scan discription file for the 3rd party IC to keepImpact happy. Sorry I can't be more specific, this work was at a previouscompany.Cheers, Syms.

MM · Answer

Symon,Yes, that is what I was asking whether. Thanks. Can you tell what you weretrying to achieve by combining these two beasts in one JTAG chain? I want tobe able to use boundary scan equipment to verify connections between thechips in the board manufacturing phase. I am still not sure if it is worththe effort and money considering that I won't get 100% pin coverage... Iwould be curious to know how many people are actually using Intellitech andsimilar tools for testing their boards? Sorry if this is OT...Thanks,/Mikhail-- To reply directly:matusov at square peg ca(join the domain name in one word and add a dot before "ca")OK.IIRC

Symon · Answer

Hi Mikhail,We did exactly as you describe, i.e. we "want[ed] to be able to use boundaryscan equipment to verify connections between the chips in the boardmanufacturing phase."! All the parts were BGAs so it was a good way to checkconnections. Also we used the JTAG on the processor to program its flashmemory with boot loader code after the boards were populated. Finally, weused just one chain because it needed a smaller connector than multiplechains.As to whether boundary scan's worth it or not, that depends on your volume,yeild, rework cost for completed units, etc.Cheers, Syms.toand

Bob · Answer

We use Corelis tools to verify ball-to-ball connectivity. Every board that we manufacture utilizes the JTAG chain to test as much of the board that is possible. Our chains involve Xilinx FPGA's and many other types of JTAG-able devices.

Bob

to

and

Virtex II Pro and 3rd party devices in one JTAG chain?

Join the Discussion

Didn't find your answer?