Determining Failing State of Cyclone IV E Between Startup Reset and Configuration

Hi Anand,

Many thanks for your detailed response, I really appreciate the effort. In answer to each of your points:

1) I measured the 4 voltages of interest (5V main supply, 3.3V for IO, 2.5V and 1.2V) during switch on. The waveforms are as follows:

Where c1 = 5V, c2 = 3.3V, c3 = 2.5V and c4 = 1.2V. The verticle scale is constant at 1V/div and the horizontal scale is also constant at 1ms/div. From the point the 5V supply turns on it takes only 1.2ms for the three FPGA supplies to start. From this point in time, the three supplies reach their rated voltages in just less than 2ms. From the Cyclone IV Device Datasheet (https://www.intel.com/content/dam/www/programmable/us/en/pdfs/literature/hb/cyclone-iv/cyiv-53001.pdf) page 1-5 states that:

"(5) The POR time for Standard POR ranges between 50 and 200 ms. Each individual power supply must reach the recommended operating range within 50 ms.

(6) The POR time for Fast POR ranges between 3 and 9 ms. Each individual power supply must reach the recommended operating range within 3 ms. "

I don't know if I'm configured for standard or fast POR, but evidently the <2ms POR meets both criteria.

2) The can't scan JTAG chain message appears when I attempt to use the "Auto Detect" button in the Programmer in Quartus Prime Lite Edition. I am not doing any other configuration steps before this - should I be?

3) This is a custom board.

4) I've checked the JTAG pins and am fairly sure they are correct. I've also checked to ensure there are no open connections or shorts here.

5) I believe the connection between Blaster and JTAG header is ok.

I am quite puzzled by the 1.2V state on the nCONFIG pin. As it is pulled up to 2.5V, surely it should be at either 0V or 2.5V in a normal logic state? Or is there additional behaviour? I have included my schematic as a pdf for your consideration. The main FPGA is presented on page 3. The JTAG header is on page 6, labelled as CON 11. My possible concern is that my supply voltages are not correct (including on JTAG) . What do you make of them? Below is a drawing of my JTAG connector (CON 11) as if you are looking into it. The notch is indicated for the Blaster connection.

Thanks again in advance.