LX1977IDU MICROSEMI [Microsemi Corporation], LX1977IDU Datasheet - Page 8

• Manufacturer Part Number: LX1977IDU
• Description: SMBus Ambient Light Sensor
• Manufacturer: MICROSEMI [Microsemi Corporation]

SMB
Copyright © 2010
Rev. 1.0, 2010-03-25
US
communicate with LX1977 must be per standard SMBus specification version 2.0 or higher.
SMBus Specification at www.smbus.org/specs.
the host.
C
OMMUNICATION
LX1977 employs the following SMBus 2.0 protocols that are also compatible to I
• Send Byte
• Receive Byte
• Write Byte
• Write Word
• Read Byte
• Read Word
The individual protocol format is shown in tables below. For a complete description of SMBus protocols, please review the
Grey shading represents cycles during which the LX1977 “owns” or “drives” the Data line. All other cycles are driven by
TM
S
Wr
P
S
1
Slave Address
Start Condition
Write (bit value of 0)
Stop Condition
Master-to-Slave
S
1
11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: [phone]
7
Slave Address
P
ROTOCOL
S
S
S
1
1
7
Table 6: SMBus Packet Protocol Diagram Element Key
Wr
1
0
Slave Address
Slave Address
Slave Address
A
1
Wr
Command Code
7
7
1
0
Table 10: Write Word Protocol:
Table 8: Receive Byte Protocol:
Table 9: Write Byte Protocol:
Table 7: Send Byte Protocol:
Analog Mixed Signal Group
A
1
8
®
Microsemi
Command Code
Wr
Wr
Rd
1
0
1
1
Rd
A
Command Code
A
A
A
A
X
1
1
8
1
Read (bit value of 1)
Acknowledge (‘0’ for an ACK, or ‘1’ for a NACK)
Slave-to-Master
Data Byte Low
Data Byte
Data Byte
Data Byte
SMBus Ambient Light Sensor
8
A
8
8
1
P
RODUCTION
Data Byte
1
A
Register Address
A
X
A
A
1
1
1
8
Data Byte High
P
P
P
1
1
8
D
A
1
ATASHEET
2
C protocols. Protocols used to
P
1
A
1
P
1
LX1977
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