Turning on VADJ from PMCU on Genesys ZU

[pfuhrman]

I have a Genesys ZU Rev. B board which comes up fine except the PMCU LED does not come on or blink at all, as it says in the reference manual.  Nor can I turn on VADJ by outputting on the LEVEL0/1 and VADJ_AUTON signals from the 3EG chip.  I have tried communicating with the ATMega over its serial port, but I get no response.  For example, "0301" should return the firmware version. 

I have a logic analyzer on J36 to observe the startup I2C activity from the PMCU, but I see no activity at main power-on.  

I'm assuming that the PMCU is working since the ZU3EG comes up, but I also need to bring up VADJ.  What's the best way to debug this function?  

Can the ATmega328 bootloader be accessed over the J38 debug port, once you load a 6 pin header?

[JColvin]

Hi @pfuhrman,

I have reached out to another engineer more familiar with the Genesys ZU about this.

Thanks,
JColvin

[pfuhrman]

Thanks, @JColvin.  Meanwhile, I have experimented with I2C from the ZU3EG, and I find that I can turn on the VADJ power controller and set the voltage with a several register settings. But the PMCU just seems to be dead.   But it took a while going through the documentation on these Infineon PMICs.   I'd like to know how much does normal operation rely on the ATmega PMCU, or is it mainly for health monitoring.  

   

[elodg]

That does not sound right. All the functions the PMCU serves is described in the reference manual, which include important ones like VADJ control or thermal cooling control. If LD21 does not blink on power-up the wake-up pattern, the PMCU is either missing its firmware or is otherwise damaged.  If there is still a bootloader in it, we can try a firmware upgrade through USB-UART, not J38. A colleague of mine will PM you with the instructions.

If firmware upgrade fails we will do an RMA. Is there a change the PMCU has been erased using an programming cable through J38?

 

[pfuhrman]

Thanks, @Elodg.  I don't see how I could have damaged it.  My work with the board has mainly been with Petalinux and FPGA fabric designs, and I have programmed QSPI for bootup. I have not done anything with J38, I was just speculating about how to see if the PMCU was doing anything at startup.  I don't see anything over I2C or the LED.   I guess that all the IRPS5401's are pre-programmed in NVM and don't need tweaking at startup, other than VADJ if requested.  For my immediate needs I can use I2C from the ZU3EG to do that.  But I am concerned if there is anything else I am missing, other than the cooling control.  For that I can jumper the fan ON.  

I would be interested in what could be done to reprogram it, if that's what's required.  I have tried to talk over USB-UART but I don't see any activity there.  But I may be able to connect an Arduino via J38 in ISP mode.  In any case, please have your colleague message me.