New Contributor
New ContributorHi Tbake8,
There are a few things that I think could be of issue. There has been a good back and forth between you and Anand, so forgive me for lack of continuity.
First, lets address your confusion about passive serial configuration. The FPGA can configure itself/be configured in a variety of ways. See chapter 8 of the Cyclone IV handbook to read about the differences between active configuration vs. passive configuration vs. JTAG configuration.
To not overcomplicate things, the way your FPGA is expecting to be configured is based on the MSEL pins. Based on your schematic your MSEL[2:0] pins are 010. This correlates to an active serial configuration method for your Cyclone IV device. See the below image, but your FPGA is expecting an active serial configuration scheme in the standard POR delay mode.
As to why you are seeing the strange voltage values on nCONFIG, I unfortunately cannot say right now.
But if you refer to the bottom of that image I posted, I circled another statement. What that statement is saying is: JTAG configuration should always work with this device, regardless of what your MSEL pins are. So that begs the question: “well why does JTAG config not work for me? When I try and “target” my device over the Quartus programmer, I can’t see the device.”
This is a good question, but I also am not sure at the current moment (☹). It looks like the pinout of your JTAG header (which is where the USB blaster plugs into) is correctly pinned out, but that is worth double checking. I think tackling and figuring out why you cant see your device over JTAG should be first priority. Then figuring out what is wrong with the nCONFIG, nSTATUS, and other related pins.
Also, be sure that Quartus Lite was correctly installed on your machine and that your drivers are up to date/correct.
Hope this was somewhat helpful.
