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Altera_Forum
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11 years ago

Cyclone III 144 QFP package forgot the ground pad on circuit board

Our circuit board guy forgot to put a ground pad on the board for the 144 pin package on the bottom of the chip. We are unable to detect it thru the JTAG port and assuming that is why. What may al...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
11 years ago

Well it turns out I was able to probe the pad thru a via with a wire and it is already grounded! Perhaps that pad is grounded thru a ground pin or on the internal leadframe or something, maybe Altera wants it grounded for noise or power issues. I'm thinking that's not the reason it can't be detected via JTAG. I put in a support request to see if they know if that pad isn't grounded USB Blaster wont detect the chip on JTAG. I doubt I will get a meaningful response, the tech support people seem to be in india and just quote documentation, no real world experience with customers or contacts with people at altera to know this.