Imx6 based custom board power reset

[snehal_jadhav]

Hi,

We are working on custom board with i.MX6Q SoC which is battery operated and using charger IC bq25890, Fuelgauge IC MAX17055. When we increase the system load or when the battery is at low charge our system resets, when we check u-boot logs we see reset cause as POR. We are not getting the possible reason for the system just reset out of nowhere. Thus we started looking into charger IC out of what I understood we disabled BATFET Full System Reset function by field BATFET_RST_EN. Please share if there is anything we are missing to get the cause of this system reset.

Thanks in Advance

 #charger #bq25890 #powerReset

[Sanket_Parekh]

Hi @snehal_jadhav ,

I hope you are doing well. Please confirm if POR_B is asserted when system gets reset.

Thanks & Regards,

Sanket Parekh

[snehal_jadhav]

Hello @Sanket_Parekh,

Thanks for your response,
For understanding POR_B assertion I have checked the reference manual of imx6, but I was unable to get how we can confirm if POR_B is asserting when system is resetting.
Can you please share how we can check/confirm if POR_B is asserted.

Thank you

snehal

[Sanket_Parekh]

Hi @snehal_jadhav ,

I hope you are doing well.

One can observe the POR_B pad using an oscilloscope when board is being reset due to heavy load or low battery.

Thanks & Regards

Sanket Parekh

[snehal_jadhav]

Hello @Sanket_Parekh,

Thanks for your response, We have observed that POR_B pad is asserted (pulled low) while the system abruptly resets when the battery is low charged and load increases. also sometimes board abruptly resets though there is no heavy load and battery is sufficiently charged.
Please find below snippets of POR_B pad when asserted while reset. Please share any step we can take in resolving this abrupt shutdown issue.

snehal_jadhav_0-1675083388834.png

snehal_jadhav_1-1675083428926.png

Thanks in advance
snehal