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Altera_Forum
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18 years ago

Stratix III wierd JTAG Config problem

I've got 2 Stratix III devices in a JTAG chain. If I power the board, I can scan the chain OK and program repeatedly but as soon as I switch off the power and re-apply, JTAG no longer works. i...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
18 years ago

Usually, an unacessable JTAG chain is caused by any of the supply voltages monitored for power-on-reset is below it's specification. These are with Stratix III: VCC, VCCL, VCCPT, VCCPD and VCCPGM. Although this is prerequisite for performing boundary scan testing, the supply voltage conditions aren't mentioned in BST chapter of device handbooks.

Or the JTAG chain itself has an inappropriate wiring.