Multiple Channel 1°C Temperature Sensors with Beta Compensation
Datasheet
5.1.6
SMBus Stop Bit
The SMBus Stop bit is defined as a transition of the SMBus Data line from a logic ‘0’ state to a logic
‘1’ state while the SMBus clock line is in a logic ‘1’ state. When the device detects an SMBus Stop bit
and it has been communicating with the SMBus protocol, it will reset its client interface and prepare
to receive further communications.
5.1.7
5.1.8
SMBus Timeout
The EMC1413 / EMC1414 supports SMBus Timeout. If the clock line is held low for longer than 30ms,
the device will reset its SMBus protocol. This function can be enabled by setting the TIMEOUT bit in
the Consecutive Alert Register (see Section 7.12).
2
SMBus and I C Compatibility
The EMC1413 / EMC1414 is compatible with SMBus and I2C. The major differences between SMBus
and I2C devices are highlighted here. For more information, refer to the SMBus 2.0 and I2C
specifications. For information on using the EMC1413 / EMC1414 in an I2C system, refer to SMSC AN
14.0 SMSC Dedicated Slave Devices in I2C Systems.
1. EMC1413 / EMC1414 supports I2C fast mode at 400kHz. This covers the SMBus max time of
100kHz.
2. Minimum frequency for SMBus communications is 10kHz.
3. The SMBus client protocol will reset if the clock is held at a logic ‘0’ for longer than 30ms. This
timeout functionality is disabled by default in the EMC1413 / EMC1414 and can be enabled by
writing to the TIMEOUT bit. I2C does not have a timeout.
4. I2C devices do not support the Alert Response Address functionality (which is optional for SMBus).
Attempting to communicate with the EMC1413 / EMC1414 SMBus interface with an invalid slave
address or invalid protocol will result in no response from the device and will not affect its register
contents. Stretching of the SMCLK signal is supported, provided other devices on the SMBus control
the timing.
5.2
SMBus Protocols
The device supports Send Byte, Read Byte, Write Byte, Receive Byte, and the Alert Response Address
as valid protocols as shown below.
All of the below protocols use the convention in Table 5.2.
Table 5.2 Protocol Format
DATA SENT
TO DEVICE
DATA SENT TO
THE HOST
# of bits sent
# of bits sent
SMSC EMC1413 / EMC1414
Revision 1.41 (02-23-12)
DATA1S5HEET
SMSC [ SMSC CORPORATION ]
