OM2NTP5332 I2C Read session register all value is 0xFF

[Libaiyi]

Directly reading data from address 0000h (EEPROM) using I2C and reading data from address 0000h (EEPROM) through NFC via a mobile app are corresponding. But when using I2C to read the session register address from 10A0h-10ADh, the values obtained are all 0xFF.

From the perspective of session registers, some registers should not default to 0XFF. How can I read the value of the session register?

[KaiLi]

Hello @Libaiyi 

Please try to the below logic:

BR

kelly

[Libaiyi]

This is a Configuration memory with a starting address of 1000h.

The data captured here corresponds to the data that can be read by mobile app

 

This is a session register with a starting address of 10A0h, all  value is 0xff.

[KaiLi]

Hello @Libaiyi 

From the I2C timing logic of your side, the reading the logic of the register is not correct. NTAG5 has two type of reading, one is to read the entire field of the register that is 4 bytes, the other is to read any field of the register, please refer to the following example to adjust your read logic.