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Altera_Forum's avatar
Altera_Forum
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17 years ago

can't scan jtag chain in customer built board

I have a custom built board with EPM570T100C3N, this is the only programmable device in the board. The other chip is a CY68013A. The USB part of the board works well, but the CPLD cannot programmed b...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
17 years ago

I don't see a problem. TCK pulldown of 1K should also work, it's a recommended value for some FPGA. USBBlaster is able to drive 1k load as well. 35 mm trace length is rather short. There's most likely another problem like bad solder joints or unstable supply voltage.