lx1977 Microsemi Corporation, lx1977 Datasheet - Page 9

• Manufacturer Part Number: lx1977
• Description: Smbus Ambient Light Sensor
• Manufacturer: Microsemi Corporation

SMB
SMBus D
LX1977 R
Copyright © 2010
Rev. 1.0, 2010-03-25
1
S
US
• When the ALS SMBus interface is not powered, it will not affect other SMBus traffic that may occur. The SMBus interface
• SMBus pull-up resistors should be provided on the system, and is not provided by the LX1977 device.
• The ALS shall NACK any SMBus operation directed to it that addresses a register that is not defined in this specification.
Package Error Correction, Alarm function and the Address Resolution protocols are not supported by this device.
Detailed descriptions of the individual register are shown below.
Register(hex) R / W
pins should be in high impedance mode when the interface is not powered.
Slave Address
R
E
EQUIREMENTS
EGISTER
-
00h
01h
02h
03h
04h
05h
06h
07h
08h
TM
FEATURING
S
1
7
Slave Address
D
R / W
R / W
R / W
R / W
R / W
R / W
7
Wr
EFINITIONS
1
0
R
R
R
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A
1
High-Threshold MSB
Low-Threshold MSB
High-Threshold LSB
Low-Threshold LSB
Wr
Command Code
Command / Status
1
0
MSB of D
LSB of D
Device Control
ID Register
A
1
8
Command Code
COUNT
COUNT
Table 13: LX1977 Register Definitions
Table 12: Read Word Protocol:
Table 11: Read Byte Protocol:
8
A
1
Analog Mixed Signal Group
Device Control and Status
ALS ADC Control
Lower byte of the Interrupt low threshold window
Higher 4 bits of the Interrupt low threshold window
Lower byte of the Interrupt high threshold window
Higher 4 bits of the Interrupt high threshold window
Lower byte of the ADC result
Higher 4 bits of the ADC result
Part Identification
S
1
®
Microsemi
Slave Address
A
1
S
1
7
Slave Address
Description
SMBus Ambient Light Sensor
7
Rd
1
1
1
A
P
RODUCTION
Rd
Data Byte Low
1
1
A
1
8
D
Data Byte
ATASHEET
8
A
1
Data Byte High
A
1
1
8
1
P
LX1977
A
1
1
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P
1