STM32WB1MMCH OTP

[luzuhua]

STM32WB1MMCH：Can other values be written again after the otp area is written to 0xFF

[STTwo-32]

Hello @luzuhua and welcome to the ST Community.

According to the RM0473,

« 1 Kbyte (128 double words) OTP (one-time programmable) for user data. The OTP data cannot be erased and can be written only once. If only one bit is at 0 the entire double word (64 bits) cannot be written anymore, even with the value 0x0000 0000 0000 0000. »

Best Regards.

STTwo-32

[luzuhua]

The first time I write 0x5a to 0x1FFF7008-0x1FFF70F7,and other addr i write 0xFF;The second time，i want to write some value to 0x1FFF70F8-0x0x1FFF73F7，but I found that I cannot write it，May I ask why this is？

[STTwo-32]

As i mentioned before, The OTP data cannot be erased and can be written only once. This should be the explication of the behavior you are having here.

Best Regards.

STTwo-32