1°C Triple Temperature Sensor with Resistance Error Correction & 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 EMC1053 via the two wire
serial interface named SMBus. The SMBus interface is used to read and write registers in the
EMC1053, which is a slave-only device. A detailed timing diagram is shown in
T
LOW
T
HIGH
T
HD:STA
T
F
T
SU:STO
SMCLK
T
HD:STA
T
R
T
HD:DAT
T
SU:DAT
T
SU:STA
SMDATA
T
BUF
P
S
S - Start Condition
S
P - Stop Condition
P
Figure 2.1 System Management Bus Timing Diagram
The EMC1053 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
# of bits sent
DATA SENT TO
THE HOST
# 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 Write Byte Protocol
START
1
SLAVE ADDRESS
7
WR
1
ACK
1
COMMAND
8
ACK
1
DATA
8
ACK
1
STOP
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 Read Byte Protocol
START
1
SLAVE
ADDRESS
7
WR
1
ACK
1
COMMAND
8
ACK
1
START
1
SLAVE
ADDRESS
7
RD
1
ACK
1
DATA
8
NACK
1
STOP
1
SMSC EMC1053
DATASHEET
9
Revision 1.37 (02-05-07)
SMSC [ SMSC CORPORATION ]
