communication issue with ADS7924 external slave via i2c

[unknown_boy]

Dear NXP Support Team,

I hope this message finds you well.

I am currently facing a communication issue with the ADS7924 external slave device interfacing with the MK22FN512VLL12 master microcontroller. Specifically, I am sending the slave address 0x49 or (0x92), but the slave seems to be acknowledging the transmission even when the address is incorrect, but slave should not acknowledge after address is incorrect.  

This behavior is critical, as it disrupts proper communication between the master and the slave. I would greatly appreciate your assistance in diagnosing this issue and any recommendations you may have to ensure proper address recognition.

[Pablo_Ramos]

Hi @unknown_boy 

Analyzing your configuration I didn't see anything off. However, you could try to test the integrity of your I2C module with an example.

Also, we don't have the required hardware in order to make the pertinent test, could you send us a screenshot of the I2C communication using a logic analyzer or an oscilloscope?

Please let me know your results.

[unknown_boy]

hi sir,

I am facing issue with ads7924 slave and master mk22fn512vll12 here slave is not acknowledging SDA line low after sending correct slave address(0x49 or 0x92) by sending exampale code from mcuxpresso ide for i2c master to slave,

after checking in oscilloscope its showing some spike or glitch in SDA line and not acknowledging at 9th bit.

[Pablo_Ramos]

Hi @unknown_boy,

An apology for the delay response.

Comparing the frame with the once shown in the ADS7924 datasheet it appears to be that is not a configuration issue, this because both frames are identical except for the ack/nack bit.

You could test the I2C module of your chip with a board-to-board communication with one of our examples (i2c_polling_b2b_transfer_master/slave). Also, you can use the configurations shown in these examples in order to communicate with ADS7924, by changing the address.

Could you check the connection of the ADS7924? Also, you can try changing the A0 to GND in order to change the address.

Please let me know your results.