95640 read OK and write not (write error on the beginning).
in this case check the eeprom package BEFORE any operation, bcose the operating voltage is clearly marked
You can check here (sorry for the bad picture it was taken by mobile and enlarged)
First row: S64S
The last digit is “S” = 1.8V-3.6V
You have to adjust the vvdi voltage to the correct value (default is 4.5V)