LX1977IDU MICROSEMI [Microsemi Corporation], LX1977IDU Datasheet - Page 10

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

Command Register 00h (R / W)
Copyright © 2010
Rev. 1.0, 2010-03-25
Index Address = 00000000b or 00h
Access = Read / Write
Default = 00000000b
Bit Definitions:
ADC_FLAG
START_ADC
Read Only
ADC_FLAG (bit 7, R): This is a status bit and is a read only bit. When START_ADC is set to 1, 0 on this bit indicates
ALS_ENA (bit 6, R / W): 0 on this bit means power down ALS and ADC of this device, 1 means power up ALS and
START_ADC (bit 5, R / W): Writing 1 to this bit will start a new ADC conversion and clear the ADC_FLAG bit.
ADC_MOD (bit 4, R / W): 0 on this bit sets ADC to one time conversion mode and 1 sets ADC to continuous mode when
TM
(Bit 5)
7
0
0
1
This register contains bits for configuring and controlling LX1977 and also bits showing LX1977 operation status.
ALS_ENA START_ADC ADC_MOD
Read / Write
Note:
ADC_MOD
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(Bit 4)
6
0
1
0
These two bits should be controlled together. When these two bits are set to 11, LX1977 will be in
continuous mode. When a restart of the continuous mode is need, 01 should be written to these bits
and then 11 should be written afterwards. In this case, ADC_FLAG, INT_FLAG and the internal
counter for INT_PERSIST_CTRL will be reset to 0.
ADC conversion is in process, 1 indicates conversion is done and the D
register 06h & 07h. Setting START_ADC to 1 will clear ADC_FLAG bit and start a new
conversion regardless the status of the ADC converter. The time needed to finish a conversion will
depend on the T
ADC.
Writing 0 to this bit stops (or disable) ADC conversion and also resets the internal interrupt
persistent control counter when ADC_MOD bit is set to 1. When this bit is 0, ADC_FLAG bit
will not be meaningful.
START_ADC bit is set to 1.
Read / Write
Disable ADC
Disable ADC and reset internal interrupt persistent control counter, ADC_FLAG and
INT_FLAG
Set ADC to one time conversion mode and start the conversion. ADC_FLAG bit will
indicate conversion status, 0 on this bit means conversion is in process, 1 means conversion
is done and data is ready in register 06h and 07h. Interrupt persistent control function is not
applicable to this mode.
Note:
1) When this mode is set, the ADC_FLAG will be set to zero right away.
2) When conversion is done, Bit 5 and Bit 4 will be changed from 10 to 00
5
automatically. If a new conversion is needed, 10 should be written to Bit5 and Bit 4
again.
Table 15: Bit 5 & 4 Definitions
Table 14: Command Register 00h
INT
Analog Mixed Signal Group
Read / Write
_SET setting in Device Control Register 01h bit 0 & 1.
®
Microsemi
4
ADC_CLK
Read / Write
3
SMBus Ambient Light Sensor
Description
P
INT_FLAG
Read / Write
RODUCTION
2
D
Read / Write
INT_ENA
ATASHEET
1
COUNT
Read Only
data is ready in
OV
LX1977
0
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