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Gowin: JTAG device detection failure (pretty scope pictures included!)

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mblinov:
Hi all, I can't seem to get JTAG programming over the Gowin U2X working for my new Gowin MiniStar-Nano board (FPGA part number is GW1NSR-2C)

Symptom: Gowin Programmer reports "Error: No Gowin devices found!"



So, here's the physical view (for what its worth):


And the "schematic":


The MiniStar-Nano is sitting on a side of double-sided adhesive tape. 3.3V on the two-pin connection on the left, 5-pin programming header that is the same pin-numbering as the U2X (TDO, TCK, TMS, TDI, GND). With 3.3V applied, I can verify the presence of 1.8V from the regulator on pin 36 (VCC1V8).

The U2X programming dongle:



Now, here's my programming routine: Below is what I see on my scope at different stages: In all cases, the channels 1-4 are TCK, TMS, TDO, TDI.

1). The "initial state": Dongle is unplugged. A free-running untriggered trace shows that everything is pulled up except TCK by 4K7 resistors up to 3V3 rail, as it should be given the presence of 4K7 pull-ups on those signals.


2). I plug in the U2X programmer, but dont touch anything on the PC. Free-running trace shows the TCK get pulled up.


3). Set scope to trigger on TMS falling edge. I then click only one button: The "Scan Device" button on the Gowin programmer:

I see the following packet appear on the scope. TCK and TMS get toggled, but nothing on TDO or TDI, although TDO stays high. I'm not really super familiar looking at JTAG packets at this level - surely the U2X should be pushing out *something* across TDI?


A close up on the first packet:


And on the second:


4). Set scope to free-running. All lines are now in a permanent state of 0V, except TDO - surely that's not right for JTAG? Shouldn't lines be left floating up to 3V3 if we're not in the middle of a packet? Atleast that's what I'm used to from SPI/I2C...


5). I disconnect the U2X from the USB port, and everything floats back up again


Any ideas anyone? Aside from the obvious user error, my thoughts:
 - I fried the MiniStar Nano FPGA board with my creative soldering technique. So naturally I purchased two of them. But soldering it again is gonna be a real pain...
 - Maybe its a programmer issue (either i fried it somehow, or something else)

Anyway thought I'd document what I'm doing so far. Going to try make another board with my spare MiniStar-Nano. Tomorrow a second U2X should arrive incase its a programmer issue.

mon2:
Just confirming that the proper device driver has been installed as per attached manual?

mblinov:
Yep, first thing I did was read that handbook to get the programmer properly installed (or atleast I hope it is):

1). Install WinUSB driver for the probe via Zadig (already done as you can see)


2). Verify it appears in my device manager (Indeed it does)


3). Gowin Programmer confirms its detected - Although there is one small aspect, of the Serial Number ("SN: <blank>") coming up seemingly empty, or set to the empty string - not sure what to think of that (see below)

mon2:
Select the lowest frequency for the JTAG clock (see your last post) and try again.

miken:
The fact that you see something on the scope for TCK/TMS suggests that your driver is OK. I would cut the TDI/TDO wires to the board and see what you get coming out of the dongle.

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