I²C Communication Issues Between STM8 and ST25R3916B

[Rance]

At the beginning of the program,

I first performed a write-then-read operation on register 00 using I²C timing.

I wrote 0x04 to register 00, and this worked correctly.

However, when I used the same method to perform a write-then-read operation on register 03,

I wrote 0x07 to register 03,

but when I read register 03, the returned value was 0x08.

 

Can you tell me why this problem might occur?

What are the possible reasons?

[Rance]

 

 

Even though I wrote 0xFF to register 0x03, the value read back is still 0x08.

[Rance]

I found out why.

 

so i should init first：