NTM88 sensor ID change to FF

[Pranav_Tonape]

hi NXP, 

I am Working with NTM88 ic for TPMS while testing (mounted on rim outside the tire ) we observed that the NTM88 ic id change to FF 

for example : consider NTM88 ic having it's ID "C927045E" while testing it showing "FFFFFFFF". 

[TomasVaverka]

Hi Pranav,

I have not heard about such an issue before, could you please share more details about your test conditions and the number of NTM88 ICs tested? I have also forwarded your question to our TPMS SW engineer and will get back to you as soon as I have her answer, likely next Monday as she is out of the office this week.

BR, Tomas

[Pranav_Tonape]

hi Tomas,
can you please brief me what are the detailed input you required i have a log with me in that log i observed tis issue, 3 NTM88 ic are work like this at run time and 2 more ic was start to send FF id at programming showing at programming as a secure mode at erasing the chip
thanks Pranav,

[TomasVaverka · Accepted solution]

Hi Pranav,

What about sensor measurements? Does the chip still gives valid values?

If sensor measurements give invalid values (underflow/overflow status returned), it means the trim section (including the unique ID) has been erased.

In your application, have you implemented functions to reprogram the flash? Are you calling TPMS_FLASH_WRITE or TPMS_FLASH_ERASE?

This happens if a reset occurs while address 0xFFBF is erased (0xFF value). During programming, care must be taken not to have glitches on the VDD or RESET line in order to avoid a reset between the moment address 0xFFBF is erased and the moment it is written again.

For more information on chip security, please refer to below application note:

https://www.nxp.com/docs/en/application-note/AN13321.pdf

BR, Tomas

[Pranav_Tonape]

thanks Tomas for your reply,
i will go through this datasheet, now how can i retrieve this issue so that NTM88 IC works as its normal specification please guide me for it.