ADRV9009-ZU11EG SOM Jumper override for PG_ALL power negotiation

Hello,

I am doing board bringup on a custom carrier for the ADRV9009-ZU11EG SOM (Rev C SOM). I've found some issues with the power supply on the carrier board to the SOM, but with some workarounds they've been dealt with.

One of the workarounds caused the PG_ALL signal to the SOM to never deassert. From this post as well as on the wiki, it is stated that a jumper can override the PG_ALL signal. The custom carrier has the same jumper setup, but the board is still not booting when in the PG_ALL "overriden" configuration (jumpered 2-3).

I tried the same override setup with the ADI eval carrier + SOM, and it failed with a PS_ERROR_OUT LED coming on. This setup boots normally with the 1-2 jumper config.

The Xilinx documentation tells that "PS_POR_B must be asserted Low at power-up and continue to be asserted for a duration of TPSPOR after all the PS supply voltages reach minimum levels." [DS925, Pg. 33]. TPSPOR being 10us minimum.

I don't know the exact timing of the PS power supply ramp-up relative to the other power supply ramp-ups (namely the 1.8V from the SOM), but wouldn't jumpering PG_ALL to 1v8_SOM violate the TPSPOR, and not be a viable boot configuration?

Regards,

-Samual

Parents
  • 0
    •  Analog Employees 
    on May 5, 2021 12:00 PM

    Hi Samual,

    If you want to override PG_CARRIER by configuring P20 with a jumper on position 2-3 it could not work because PS_POR_B pin of FPGA would just have a pull up to 1V8 rail and this rail starts up after 0V85_PL and 0V85_PS having other FPGA rails coming up after that. As you pointed out the PS_POR_B needs to be low until all the rails achieved their minimum valid voltage level plus TPSPOR.

    As mentioned on this post to override PG_CARRIER you have to connect PG_SOM to PG_ALL.

    We are going to fix this issue on the next version of the board.

    Thanks,

    Florin

  • Hi Florin,

    Thanks for the reply.

    I misread that linked post, my apologies. I tested the config mentioned there on my Rev C CRR/SOM setup, but I am still running into a boot issue with the PS_ERR_OUT LED coming on. I connected P18 Pin 1 to P18 Pin 2, and also jumpered P18 Pin 1 to P20 Pin 2. This has PG_SOM connected to the EN_PWR_CRR on P18, and also PG_SOM to PG_ALL.

    Is this correct?

    I read the ZU11EG device registers via JTAG, and it is indicating a CSU_BR_ERR with the error value 0x80003B00. The 0x3B error means "Reading failed from the selected boot device" (CRR SD Card is selected, bootmode registers are [1110]). I can boot off the SD card when in the normal jumper config (P18 Pin 1 to Pin 2, P20 Pin 1 to Pin 2).

    I'd like to make sure I can boot with whatever PG_ALL override config on the ADI CRR/SOM setup so I am confident that it should work on my custom carrier/SOM setup.

    Best,

    -Samual

  • +1
    •  Analog Employees 
    on May 7, 2021 11:43 AM in reply to Samual

    Hi Samual,

    Your test setup is correct: P18 jumper on 1-2 and P18 pin1 connected to P20 pin2. I was able to reproduce that the system does not boot up with this configuration showing PS_ERR_OUT LED on. Looking a little bit closer to the schematic I noticed that the carrier SD card is supplied from carrier 3V3 which explains the boot up issue: SOM is powered up first and then the carrier is powered up when PG_SOM becomes high (this also release PS_POR_B that is PG_ALL) which probably makes the SOM to try booting up from carrier SD card which doesn't have yet the 3V3 supply.

    To confirm the above assumption I tried the following jumper configuration: P18 jumper on 2-3 and P18 pin1 connected to P20 pin2. This configuration starts the power up of SOM and CARRIER when the 12V supply is available and SOM boots up when PG_SOM is high. Since this jumper configuration is booting up successfully I assume that carrier 3V3 comes up before the SOM is powered up (PG_SOM = PG_ALL = high).

    I recommend to make the following changes to your carrier design:

    1. Connect PG_SOM to P20 pin 3 instead of R271 pulled up to 1V8_SOM

    2. Supply the carrier SD card from 3V3 rail coming from SOM which is available at P12 pin D1.

    Before making these changes would be good if you could prototype them on existing carrier.

    Thanks,

    Florin

Reply
  • +1
    •  Analog Employees 
    on May 7, 2021 11:43 AM in reply to Samual

    Hi Samual,

    Your test setup is correct: P18 jumper on 1-2 and P18 pin1 connected to P20 pin2. I was able to reproduce that the system does not boot up with this configuration showing PS_ERR_OUT LED on. Looking a little bit closer to the schematic I noticed that the carrier SD card is supplied from carrier 3V3 which explains the boot up issue: SOM is powered up first and then the carrier is powered up when PG_SOM becomes high (this also release PS_POR_B that is PG_ALL) which probably makes the SOM to try booting up from carrier SD card which doesn't have yet the 3V3 supply.

    To confirm the above assumption I tried the following jumper configuration: P18 jumper on 2-3 and P18 pin1 connected to P20 pin2. This configuration starts the power up of SOM and CARRIER when the 12V supply is available and SOM boots up when PG_SOM is high. Since this jumper configuration is booting up successfully I assume that carrier 3V3 comes up before the SOM is powered up (PG_SOM = PG_ALL = high).

    I recommend to make the following changes to your carrier design:

    1. Connect PG_SOM to P20 pin 3 instead of R271 pulled up to 1V8_SOM

    2. Supply the carrier SD card from 3V3 rail coming from SOM which is available at P12 pin D1.

    Before making these changes would be good if you could prototype them on existing carrier.

    Thanks,

    Florin

Children
  • Thanks Florin!

    I was able to get that setup to work on the ADI CRR. I found an additional issue on my custom carrier with the power supply, so I had to bypass the entire power circuitry of my custom carrier and supply 12V to the SOM from a wall power supply... This also means that the SD card on the carrier will not be powered.

    To get around that, I jumpered PG_SOM directly to PG_ALL (since the SOM is now isolated from the CRR power), and was able to boot off the SOM microSD card.

    This is a temporary workaround, but will let me do some further testing and debugging before another carrier board spin.

    Thanks again for the quick assistance!

    Best,

    -Samual