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Checking the chain continuity is a very basic JTAG operation, not specific to Altera devices in any way. The JTAG access algorithm is described in various Altera documents (and a nearly inifinite amount of internet resources).
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I'm interested in finding out what Quartus does when I ask it to "Auto Detect" in the programmer and it comes back with the device IDs on the chain. Which set of JTAG commands it sends.
Could you please point to those documents from altera and at least a couple of the most useful internet resources ? I've already went through everything in Altera's configuration handbook.
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Not recognizing the chain means that one of the four signals is either unconnected, wrongly connected or shorted. Almost easy to grasp to my opinion. Another possible issue is a missing or out-of-specification supply, e. g. missing 2.5 V VCCA at a Cyclone III device.
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Thanks for the tips, we're working on finding out the problem. It is exaggerated by the fact that 3 boards that came from the plant show the same problem.
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