In the event that the SMBus Master is RESET while the LM95231 is transmitting on the SMBDAT line, the LM95231 must be returned to a known state in the communication protocol. This may be done in one of two ways:
- When SMBDAT is LOW, the LM95231 SMBus state machine resets to the SMBus idle state if either SMBDAT or SMBCLK are held low for more than 35ms (tTIMEOUT). Note that according to SMBus specification 2.0 all devices are to timeout when either the SMBCLK or SMBDAT lines are held low for 25-35ms. Therefore, to insure a timeout of all devices on the bus the SMBCLK or SMBDAT lines must be held low for at least 35ms.
- When SMBDAT is HIGH, have the master initiate an SMBus start. The LM95231 will respond properly to an SMBus start condition at any point during the communication. After the start the LM95231 will expect an SMBus Address address byte.