Why the data can’t be written into EEPROM?

[EDA_hg81]

I used the scope to check, the data and clock are toggling.

Only have glitch during acknowledge time when scl is low.

The writing protect pin is connected to ground.

What are the possible reasons?

Thanks.

 

[tkbits]

Time.

The write time is much slower than read time. Completing the I²C transfer only starts the write cycle.

Some chips will not acknowledge while they are in the write cycle, you can repeatedly attempt a zero-length write until you get an acknowledge.

Or you can simply wait some arbitrarily large amount of time, for example 10 ms, before attempting to read the written data.

 

[EDA_hg81]

yes. you are right.

I didn't wait long enough for writing.

Take care and best regards.