Can't simulate signals to get into force usb recovery mode to TX2

I am trying to get into force usb recovery mode for TX2, instead of using buttons I want to simulate the signals coming from an FPGA but can’t seem to get into force recovery mode. Here are the steps I did:

With the device powered off I plug in the micro B cable. I power on fully then drive FORCE_RECOV# low. With FORCE_RECOV# still low, I create a 200 ms active low pulse with RESET_IN#, lastly I keep FORCE_RECOV# for another 2 seconds. I checked on the oscilloscope and see that the signals going to TX2 are behaving how I described but when I do lsusb I fail to see the Nvidia. Are there more to it then the steps I described above? Any help will be much appreciated.

Hi, assume the board can enter recovery mode by manually pressing button, right? So did you try your FPGA configuration without USB cable plug-in?

Hi Trumany, if I don’t connect the microB how can I know if I’m in force recovery mode? Do I need to set any signals to a default state prior to force recovery? Thanks did your help.

I mean plug in cable after reset. No other signals needed to be set. Is there any other interface connected between your FPGA and TX2 during power on?

Thanks for the quick reply. Do you mean plug in after the reset_out signal of the power up sequence or reset_in (the reset button) used during force recovery? I haven’t tried it yet since the instructions said to plug it in before power on but I can give it a try. There are no interfaces between the TX2 and FPGA.

I mean after that “lastly I keep FORCE_RECOV# for another 2 seconds”.
That is strange then, it is a simple action to enter recovery mode… Are you sure the board can enter recovery mode by manually keep pressing recovery button first and then press reset button?

We created our own carrier board with an FPGA to interface TX2. We can power on TX2 and USB and everything works. I am trying to get TX2 into force recovery mode now. I can see that the current drops when I try to simulate the signals into recovery mode with the FPGA which goes directly to the TX2. I compared it to the actual TX2 carrier board and see that the current also drops when I place it into force recovery mode. But for our board, I fail to see Nvidia when I do lsusb, is there any reason why I cannot see this line?

Did you try a longer delay on RESET_IN#? Such as 400ms or more? If still same, can you try using FPGA to control recovery pin but use a button to run RESET? I’m concerning that the pull up voltage in FPGA will affect RESET_IN# pin status during TX2 reset process.