NTAG I2C block 0x39 (I2C side) confusion - PWD and multiple writes

[nick002025]

For NTAG I2C parts, I have a little bit of confusion regarding block 0x39 (I2C interface) that isn't clear in the datasheet.

1. Can I change the password by writing to the PWD field in block 0x39 multiple times or it is OTP?
2. If I set a password with a write to 0x39 and at sometime in the future I need to write to 0x39 to set one of the other configurations, such as PT_I2C, will I overwrite the password or do I need to remember the password since it always read back as 0?

[danielchen]

Hi @nick002025 :

Changing the PWD configuration area, dependent on REG_LOCK_I2C bit

Setting both bits REG_LOCK_I2C and REG_LOCK_NFC to 1b, permanently locks write access to register default values.

Regards

Daniel