Datasheet
D7 D6 D5 D4 D3 D2 D1 D0
1 9 1 9
Ack
by
LM95234
Start by
Master
Repeat
Start by
Master
R/W
Frame 1
Serial Bus Address Byte
Frame 2
Command Byte
Ack
by
LM95234
D7 D6 D5 D4 D3 D2 D1 D0
1 9 1 9
Ack
by
LM95234
R/W
Frame 3
Serial Bus Address Byte
Frame 4
Data Byte from the LM95234
No Ack
by
Master
Stop
by
Master
SMBCLK
SMBDAT
SMBCLK
(Continued)
SMBDAT
(Continued)
A5 A3 A2 A0A6 A4 A1
A5 A3 A2 A0A6 A4 A1
D7 D6 D5 D4 D3 D2 D1 D0
1 9 1 9
Ack
by
LM95234
Start by
Master
R/W
Frame 1
Serial Bus Address Byte
Frame 2
Data Byte from the LM95234
NoAck
by
Master
SMBCLK
SMBDAT
Stop
by
Master
A5 A3 A2 A0
A6 A4
A1
D7 D6 D5 D4 D3 D2 D1 D0
1 9 1 9
Ack
by
LM95234
Start by
Master
R/W
Frame 1
Serial Bus Address Byte
Frame 2
Command Byte
Ack by
LM95234
SMBCLK
SMBDAT
A5 A3 A2 A0A6 A4 A1
Stop
by
Master
LM95234
SNIS136D –AUGUST 2006–REVISED MARCH 2013
www.ti.com
Figure 20. Serial Bus Write to the Internal Command Register
Figure 21. Serial Bus Read from a Register with the Internal Command Register preset to desired value.
Figure 22. Serial Bus Write followed by a Repeat Start and Immediate Read
SERIAL INTERFACE RESET
In the event that the SMBus Master is RESET while the LM95234 is transmitting on the SMBDAT line, the
LM95234 must be returned to a known state in the communication protocol. This may be done in one of two
ways:
1. When SMBDAT is LOW, the LM95234 SMBus state machine resets to the SMBus idle state if either
SMBDAT or SMBCLK are held low for more than 35ms (t
TIMEOUT
). 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.
2. When SMBDAT is HIGH, have the master initiate an SMBus start. The LM95234 will respond properly to an
SMBus start condition at any point during the communication. After the start the LM95234 will expect an
SMBus Address address byte.
20 Submit Documentation Feedback Copyright © 2006–2013, Texas Instruments Incorporated
Product Folder Links: LM95234