Datasheet

SDA
SCL
S P
START condition, or
START repeat condition
STOP condition
SCL
SDA
START
STOP
1 2 6 7
8
9
1 2
8
9
MSB
7-bit Slave Address
R/W
Direction
Bit
Acknowledge
from the Device
MSB
Data Byte
*Acknowledge
or Not-ACK
ACK N/ACK
Repeated for the Lower Data Byte
and Additional Data Transfers
LSB LSB
Bus Activity:
Master
SDA Line
Bus Activity:
Slave
Start
Slave
Address
A
C
K
S
Address
A
C
K
S
Start
Slave
Address
A
C
K
N
A
C
K
P
Stop
Data
0 1
Register
7-bit Address 7-bit Address
A
C
K
A
C
K
A
C
K
S
P
Stop
Bus Activity:
Slave
SDA Line
Bus Activity:
Master
Slave
Address
Address Data
Start
0
Register
7-bit Address
DS92LX2121, DS92LX2122
www.ti.com SNLS330I –MAY 2010–REVISED APRIL 2013
To start any data transfer, the DS92LX2121 / DS92LX2122 must be configured in the proper I2C mode. Each
device can function as an I
2
C slave proxy or master proxy depending on the mode determined by M/S pin. The
Ser/Des interface acts as a virtual bridge between the host device and the remote device. When the M/S pin is
set to HIGH, the device is treated as a slave proxy; and acts as a slave on behalf of the remote slave. When
addressing a remote peripheral or Serializer/ Deserializer (not wired directly to the host device), the slave proxy
will forward any byte transactions sent by the host controller to the target device. When M/S pin is set to LOW,
the device will function as a master proxy device, and acts as a master on behalf of the I
2
C master controller.
Note that the devices must have complementary settings for the M/S configuration. For example, if the Serializer
M/S pin is set to HIGH then the Deserializer M/S pin must be set to LOW and vice-versa.
Figure 24. Write Byte
Figure 25. Read Byte
Figure 26. Basic Operation
Figure 27. START and STOP Conditions
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Product Folder Links: DS92LX2121 DS92LX2122