topic Re: i.MX8M Mini internal IO pullup/pulldown ERR050080 "continuously driven" in i.MX Processors

i.MX8M Mini internal IO pullup/pulldown ERR050080 "continuously driven"

Sylvain_B — Tue, 05 Nov 2024 10:46:55 GMT

Hello,

According to ERR050080 in Errata IMX8MM_0N87W, "There is a degradation of the internal IO pullup/pulldown capability when the IO pads are continuously driven in the opposite logic level,"

What is the meaning of continuously? more than 1 millisecond, 1 minute, or 1 hour???

On my design, The IO pad could be driven in the opposite logic level of internal Pullup /pullodwn resistor during software boots. After, the software disable the internal pullup/pulldown.

It's not continously, but it could be more than several tens of seconds.

Do you think it could be be a problem?

Remark: the operating temperature is -20/+70°C.

Best Regards.

Sylvain

Re: i.MX8M Mini internal IO pullup/pulldown ERR050080 "continuously driven"

Manuel_Salas — Thu, 07 Nov 2024 17:14:52 GMT

Hello @Sylvain_B

There is not documented exact "time" to describe continuously. The errata ERR050080 impact to the operations like a communication protocol that use changes in the line to the opposite state of the pull at 3.3v, that means continuously.

As the workaround of this Errata, is recommended to use external pulls and disable from software.

Best regards,

Salas.

Re: i.MX8M Mini internal IO pullup/pulldown ERR050080 "continuously driven"

Sylvain_B — Fri, 08 Nov 2024 10:38:39 GMT

=> So, can you confirm that if the IO pad is driven at the logic level opposite to the internal pullup/pullodwn resistor during software startup and then the software disables the internal pullup/pulldown after several tens of seconds, there won't be a problem?

Alternatively , In the first version of the erratasheet (Rev 0) 01/2019, it is mentioned that the impedance pad is downgraded (20k -> 92k). Could you please confirm that only the resistor value is affected on theand that the IO will still be functional (without the internal PU/PD resistor.
Best Regards

Re: i.MX8M Mini internal IO pullup/pulldown ERR050080 "continuously driven"

Manuel_Salas — Tue, 12 Nov 2024 15:06:34 GMT

Hello @Sylvain_B

If pull-up/Pull-down resistors are not required (internal or external), it should works well, there is not related known issue, but anyway is recommended to disable the the Pull resistors by software as you are doing.

Best regards,

Salas.