MCF8316A: no ACK signal

Hi Joshua,

Thank you for the help.

The customer tried the address from 0 to 127, but still did not receive a chip ACK. VM is 24 V, DVDD = 1.5 V, AVDD = 3.3 V, CP pin is 28.7 V. Is the voltage at CP expected?

The two MCF8316A chips on the PCB measure the same voltage state. 

Thanks and Regards,

Cherry

Hi Cherry,

Cherry Zhou said:

Is the voltage at CP expected?

We expect the voltage at CP to be 4.0 V to  5.5 V above VM,  so 28.7 V at CP is expected.

I am having trouble seeing the logic analyzer capture, could I be provided with a higher resolution image of the SDA and SCL signal capture?

Regards,

Joshua

Hi Joshua,

Can you please see the figure below:

Thanks and regards,

Cherry

Hi Cherry,

I can see the image a lot more clearly now, thank you. We will aim to provide a response by the end of next week.

Regards,

Joshua

Hi Cherry,

I2C data looks fine. A quick check on the Speed Pin. Can you also verify AVDD pin is stable or toggling and also Speed pin is stable high. This is to check if device is not entering sleep if mode is already configured for sleep.

Thanks and Best Regards,

Venkatadri S

Hi Venkatadri S,

AVDD 3.3 V is stable and the customer attempts to keep the Speed pin high, but there were no improvements.

They also suspects that the chip may enter sleep mode, but it cannot exit sleep when Speed is high.

Thanks and regards,

Cherry

Hi Cherry,

Just to take a step back on this. Is it possible to blue wire the EVM to this device and try a I2C address scan?

Thanks and Best Regards,

Venkatadri S

Hi Venkatadri S,

The chip is detected on the GUI when connected to the EVM. The default address on the GUI is 0x1which has not been modified, and the VM voltage value can be read. 

Thanks and regards,

Cherry