TMD27721 Datasheet, PDF (14/35 Pages) TEXAS ADVANCED OPTOELECTRONIC SOLUTIONS – DIGITAL ALS and PROXIMITY MODULE

TMD2772
DIGITAL ALS
and PROXIMITY MODULE
TAOS147E − DECEMBER 2012
Interrupts
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 its status is available in the status register (0x13), the output of the interrupt state can be enabled using the
proximity interrupt enable (PIEN) or ALS 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 ALS CH0 data (C0DATA) falls outside of the desired
light level range, as determined by the values in the ALS interrupt low threshold registers (AILTx) and ALS
interrupt high threshold registers (AIHTx). Likewise, an out-of-range proximity interrupt can be generated when
lid ^{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 thresholds are evaluated in sequence, first the low threshold, then the high
a _{threshold. As a result, if the low threshold is set above the high threshold, the high threshold is ignored and only}
the low threshold is evaluated.
v _{To further control when an interrupt occurs, the device provides a persistence filter. The persistence filter allows}
ill ^{the user to specify the number of consecutive out-of-range ALS or proximity occurrences before an interrupt}
is generated. The persistence filter register (0x0C) allows the user to set the ALS persistence filter (APERS)
and the proximity persistence filter (PPERS) values. See the persistence filter register for details on the
t _{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).
AG ^{t s PIHTH(r0x0B), PIHTL(r0x0A) PPERS(r0x0C, b7:4)}
s ⁿ _Prox
Prox
m ^{te Integration ADC}
Prox
Data
Upper Limit
Lower Limit
Prox Persistence
a _{on CH1}
Technical ^{c CH0}
PILTH(r09), PILTL(r08)
AIHTH(r07), AIHTL(r06)
APERS(r0x0C, b3:0)
CH0
ADC
CH0
Data
Upper Limit
Lower Limit
ALS Persistence
AILTH(r05), AILTL(r04)
Figure 10. Programmable Interrupt
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