S32K3 FlexIO I2C issues

[iverson3ya]

I currently have two issues with I2C FlexIO:

1. The timing does not match the standard I2C specifications, particularly not meeting the tHD;DAT and tSU;DAT requirements. Is it possible to adjust this?

iverson3ya_0-1716792589008.png

2. When using FlexIO's I2c_AsyncTransmit, it gets stuck in an interrupt and doesn't exit. This doesn't happen the first time but occurs after polling a few times, and then it continuously triggers the interrupt without exiting.

iverson3ya_1-1716792786538.png

[danielmartynek]

Hello @iverson3ya,

The FlexIO just emulates the I2C protocol, there are some limitations.

The tHD;DAT and tSU;DAT parameters cannot be adjusted.

AN5133 Emulating I2C Bus Master by using FlexIO

https://www.nxp.com/docs/en/application-note/AN5133.pdf

AN12174 Using FlexIO to emulate communications and timing peripherals

https://www.nxp.com/docs/en/application-note/AN12174.pdf

What version of the RTD drivers do you use?

Does the address get acknowledged? Is the Slave device holding the bus low when the issue occurs?

What is the baudrate, and have you tried using lower baudrates?

Regards,

Daniel

[iverson3ya]

Perhaps because I'm using FreeRTOS, two tasks are entering I2c_AsyncTransmit simultaneously, causing an infinite loop. I added a critical section around I2c_AsyncTransmit and increased the interval between uses. So far, it hasn't happened again.

Could this be the cause?

thanks

[danielmartynek]

Thanks for the update @iverson3ya,

A single peripheral instance should be handled by one task.

BR, Daniel