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Altera_Forum
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17 years ago

Cyclone III user I/O stay LOW during JTAG configration

Hi,all I found all user I/Os became LOW during JTAG configruation in my situation. The device is Cyclone III 3C35. However, it is said that user I/Os must be tri-stated during JTAG configuration i...
Altera_Forum's avatar
Altera_Forum
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17 years ago

Nothings's wrong I think.The said pin is dual pupose, in configuration state it's dedicated to AS interface. I would expect, that this behaviour is only present, when an AS configuration scheme is selected by MSEL pinstrapping, but I'm not sure about. It should be unaffeceted by Quartus device and pin options, that are only in effect in user mode.