Hello ALL, i would be very nice to get an answer for the next question.... I have a F1xx µC and a serial EEPROM. The code I was plaing with is: .... SMB0CN = 0x44; -> (1) MemoryPower(pwm);->gives 5V to the memory TimeDelay(nSec); //SMB0CN = 0x44; -> (2) InterruptSmbusON; ReadSmbus();-> like in App-AN113 from Cygnal. In the case 1 I get my smbus communication stalled in the ReadSmbus() with a periodicity of 10%,(it does't get out of while(sm_busy)). But in the case (2)it seems to be ok. The ReadSmbus and smbus irq start after the memory got its power, and it means the initialization of SMB0CN plays some role here and the place of it in the code leads to different initializations of the state machine(?). And in my case 1, the absence of 5V for the memory brought the state machine to the wrong start condition. Could somebody please say something to it? Thank you very much, with best wishes, A.