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Altera_Forum
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8 years ago

JTAG Programming successfull but no effect at the ouput

I am using a Cyclone III EP3C120F484 device for my custom board. When I connect the USB Blaster and run the JTAG programmer in Quartus, the programming is done with no error. The code is just writt...
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Altera_Forum
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8 years ago

CONF_DONE should be HIGH after programming. This is true when programming using any method. When in JTAG mode the programmer monitors the status of CONF_DONE through the JTAG port.

Before and during programming, user I/O will be tri-stated and pulled up via internal pull-up resistors. So, if "Everything is tied to 3.3V" - and CONF_DONE is LOW, then your device is not programmed and you are looking at the internal pull-ups that are active on each I/O pin.

Some other things to check:

1) Is nCE tied to GND?

2) Are both CONF_DONE & nSTATUS pulled up externally?

Have you looked through the "configuration, design security, and remote system upgrades in the cyclone iii device family (https://www.altera.com/content/dam/altera-www/global/en_us/pdfs/literature/hb/cyc3/cyc3_ciii51016.pdf)" section of the handbook?

Cheers,

Alex