tcs3771 ETC-unknow, tcs3771 Datasheet - Page 13

• Manufacturer Part Number: tcs3771
• Description: Color Light-to-digital Converter With Proximity Sensing
• Manufacturer: ETC-unknow

Interrupts
The LUMENOLOGY r Company
The interrupt feature simplifies and improves system efficiency by eliminating the need to poll the sensor for
light intensity or proximity values outside of a user-defined range. While the interrupt function is always enabled
and it’s status is available in the status register (0x13), the output of the interrupt state can be enabled using
the proximity interrupt enable (PIEN) or RGBC interrupt enable (AIEN) fields in the enable register (0x00).
Four 16-bit interrupt threshold registers allow the user to set limits below and above a desired light level and
proximity range. An interrupt can be generated when the RGBC Clear data (CDATA) falls outside of the desired
light level range, as determined by the values in the RGBC interrupt low threshold registers (AILTx) and RGBC
interrupt high threshold registers (AIHTx). Likewise, an out-of-range proximity interrupt can be generated when
the proximity data (PDATA) falls below the proximity interrupt low threshold (PILTx) or exceeds the proximity
interrupt high threshold (PIHTx). It is important to note that the low threshold value must be less than the high
threshold value for proper operation.
To further control when an interrupt occurs, the device provides a persistence filter. The persistence filter allows
the user to specify the number of consecutive out-of-range RGBC or proximity occurrences before an interrupt
is generated. The persistence register (0x0C) allows the user to set the RGBC persistence (APERS) and the
proximity persistence (PPERS) values. See the persistence register for details on the persistence filter values.
Once the persistence filter generates an interrupt, it will continue until a special function interrupt clear command
is received (see command register).
Red
Integration
Clear
Prox
Clear
Prox
ADC
ADC
Figure 13. Programmable Interrupt
Clear
Data
Prox
r
Data
PIHTH(r 0x0B), PIHTL(r 0x0A)
PILTH(r 09), PILTL(r 08)
AIHTH(r 07), AIHTL(r 06)
AILTH(r 05), AILTL(r 04)
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Lower Limit
Lower Limit
Upper Limit
Upper Limit
COLOR LIGHT-TO-DIGITAL CONVERTER
PPERS(r 0x0C, b7:4)
APERS(r 0x0C, b3:0)
RGBC Persistence
Prox Persistence
r
with PROXIMITY SENSING
Copyright E 2011, TAOS Inc.
TAOS110A − MARCH 2011
TCS3771
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