topic Re: I2C communication getting stuck during data read from FRAM in MCX Microcontrollers

I2C communication getting stuck during data read from FRAM

bcihpaivnan — Wed, 17 Sep 2025 14:05:21 GMT

Hi all,

I have recently started working on LPC55S69 controller and i am trying to read data from FRAM over the I2C bus. But some time i am facing the issue to read the data from FRAM as my code is getting stuck while reading the data. i have configured the I2C timeout but not sure if it is being used correctly or not. Also, i am using "I2C_MasterTransferBlocking" for my purpose. Can someone with good knowledge on this topic guide me how to use this timeout and how to improve my i2c communication so that it won't get stuck during communication.

TIA.

Re: I2C communication getting stuck during data read from FRAM

Omar_Anguiano — Mon, 22 Sep 2025 18:43:24 GMT

The timeout value can be set with I2C_MasterSetTimeoutValue().

But first, you need to ensure that timeout is enabled on CFG register. Then you will chose if the timeout will be event caused or by SCL line. With the timeout, you can choose the action to recover the bus. If the slave is holding the bus, then the master can recover by manually sending SCL pulses until SDA is released.

BR,
Omar

Re: I2C communication getting stuck during data read from FRAM

bcihpaivnan — Tue, 23 Sep 2025 13:42:59 GMT

Thank you for the reply. timeout is set during the I2c initialization using I2C_MasterSetTimeoutValue() function. But how can i ensure if timeout is enabled on CFG register can you guide on this?

regards.

Re: I2C communication getting stuck during data read from FRAM

Omar_Anguiano — Tue, 23 Sep 2025 17:53:42 GMT

The CFG register has a field that when it is set, the timeout is enabled.
If you check the I2C_MasterSetTimeoutValue() function, it only writes to the timeout register field, but it does not enable the timeout.
The config for MasterInit() has a field to set the timeout.

BR,
Omar

Re: I2C communication getting stuck during data read from FRAM

bcihpaivnan — Wed, 24 Sep 2025 06:22:14 GMT

Again thank you for the reply and sorry for sounding like noob but i could not find anything related to CGF register.

The CFG register has a field that when it is set, the timeout is enabled.

Can you suggest any Api available or method to set that field? i am using MCUExpresso IDE.

Regards.

Re: I2C communication getting stuck during data read from FRAM

Omar_Anguiano — Wed, 24 Sep 2025 18:34:28 GMT

This is the CFG register on the User Guide:

You can enable it through MasterInit(); by setting the variable masterConfig->enableTimeout

BR,
Omar