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luzuhua
Associate
August 26, 2025
Question

STM32WB1MMCH OTP

  • August 26, 2025
  • 1 reply
  • 367 views

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

1 reply

STTwo-32
STTwo-32
Technical Moderator
August 26, 2025

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

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    L
    luzuhuaAuthor
    Associate
    August 26, 2025

    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
    STTwo-32
    Technical Moderator
    September 23, 2025

    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

    To give better visibility on the answered topics, please click on Accept as Solution on the reply which solved your issue or answered your question.
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