1°C Triple Temperature Sensor with Beta Compensation and Hotter of Two Zones
Datasheet
Note 2.2 See SMSC Applications for Application Notes and Guidelines when measuring GPU
processor diodes and CPU processor diodes.
2.3
System Management Bus Interface Protocol
A host controller, such as an SMSC I/O controller, communicates with the EMC1043 via the two wire
serial interface named SMBus. The SMBus interface is used to read and write registers in the
EMC1043, which is a slave-only device. A detailed timing diagram is shown in Figure 2.1.
TLOW
THIGH
THD:STA
TSU:STO
TR
TF
SMCLK
THD:STA
THD:DAT TSU:DAT
TSU:STA
SMDATA
TBUF
S
S
P
P
S - Start Condition
P - Stop Condition
Figure 2.1 System Management Bus Timing Diagram
The EMC1043 implements a subset of the SMBus specification and supports Write Byte, Read Byte,
Send Byte, and Receive Byte protocols as shown. In the tables that describe the protocol, the “gray”
columns indicate that the slave is driving the bus.
All of the below protocols use the following convention:
DATA SENT
TO DEVICE
DATA SENT TO
THE HOST
# of bits sent
# of bits sent
2.3.1
Write Byte
The Write Byte is used to write one byte of data to the registers as shown in Table 2.3.
Table 2.3 Write Byte Protocol
START
SLAVE ADDRESS
WR
ACK
COMMAND
ACK
DATA
ACK
STOP
1
7
1
1
8
1
8
1
1
2.3.2
Read Byte
The Read Byte protocol is used to read one byte of data from the registers as shown in Table 2.4.
Table 2.4 Read Byte Protocol
SLAVE
ADDRESS
SLAVE
ADDRESS
START
WR
ACK
COMMAND
ACK
START
RD
ACK
DATA
NACK
STOP
1
7
1
1
8
1
1
7
1
1
8
1
1
SMSC EMC1043
9
Revision 1.37 (09-05-06)
DATASHEET
SMSC [ SMSC CORPORATION ]
