CAP1088 Datasheet, PDF (40/72 Pages) SMSC Corporation – 8 Channel Capacitive Touch Sensor with 8 LED Drivers

5.7
8 Channel Capacitive Touch Sensor with 8 LED Drivers
Datasheet
„ ‘1’ - The WAKE pin will be asserted high when a touch is detected while the device is in Standby.
It will also be used to wake the device from Deep Sleep when driven high.
Bit 5 - BLK_DIG_NOISE - Determines whether the digital noise threshold is used by the device.
„ ‘0’ - The digital noise threshold is used. If a delta count value exceeds the noise threshold but does
not exceed the touch threshold, then the sample is discarded and not used for the automatic re-
calibration routine.
„ ‘1’ (default) - The noise threshold is not used. Any delta count that is less than the touch threshold
is used for the automatic re-calibration routine.
Bit 4 - BLK_ANA_NOISE - Determines whether the analog noise flag setting will block a touch
detection as well as the analog calibration routine.
„ ‘0’ (default) - If the analog noise bit is set, then a touch is blocked on the corresponding channel
and will force the analog calibration routine to retry.
„ ‘1’ - A touch is not blocked even if the analog noise bit is set. Likewise, the analog calibration
routine will not retry if the analog noise bit is set.
Bit 3 - MAX_DUR_EN - Determines whether the maximum duration recalibration is enabled for non-
grouped sensors.
„ ‘0’ (default) - The maximum duration recalibration functionality is disabled. A touch may be held
indefinitely and no re-calibration will be performed on any sensor.
„ ‘1’ - The maximum duration recalibration functionality is enabled. If a touch is held for longer than
the MAX_DUR bit settings, then the re-calibration routine will be restarted (see Section 5.8).
Sensor Enable Registers
Table 5.10 Sensor Enable Registers
ADDR R/W
REGISTER
B7
B6
B5
B4
B3
B2
B1
B0
DEFAULT
21h
R/W
Sensor Enable CS8_EN CS7_EN CS6_EN CS5_EN CS4_EN CS3_EN CS2_EN CS1_EN
FFh
The Sensor Enable registers determine whether a Capacitive Touch Sensor input is included in the
sampling cycle. The length of the sampling cycle is not affected by the number of sensors measured.
Bit 7 - CS8_EN - Enables the CS8 input to be included during the sampling cycle.
„ ‘0’ - The CS8 input is not included in the sampling cycle.
„ ‘1’ (default) - The CS8 input is included in the sampling cycle.
Bit 6 - CS7_EN - Enables the CS7 input to be included during the sampling cycle.
Bit 5 - CS6_EN - Enables the CS6 input to be included during the sampling cycle.
Bit 4 - CS5_EN - Enables the CS5 input to be included during the sampling cycle.
Bit 3 - CS4_EN - Enables the CS4 input to be included during the sampling cycle.
Bit 2 - CS3_EN - Enables the CS3 input to be included during the sampling cycle.
Bit 1 - CS2_EN - Enables the CS2 input to be included during the sampling cycle.
Bit 0 - CS1_EN - Enables the CS1 input to be included during the sampling cycle.
Revision 1.1 (08-05-09)
40
DATASHEET
SMSC CAP1088