CAP1208_15 Datasheet, PDF (29/64 Pages) Microchip Technology – 8-Channel Capacitive Touch Sensor

CAP1208
5.6 Configuration Registers
TABLE 5-9: CONFIGURATION REGISTERS
Addr R/W Register
20h R/W Configuration
44h
R/W
Configuration
2
B7
TIME
OUT
-
B6
-
BC_
OUT_
RECAL
B5
DIS_
DIG_
NOISE
BLK_
PWR_
CTRL
B4
DIS_
ANA_
NOISE
BC_
OUT_
INT
B3
B2
B1
B0 Default
MAX_
DUR_EN
-
-
-
20h
SHOW_ DIS_ ACAL INT_
RF_
RF_ _FAIL REL_ 40h
NOISE NOISE _INT
n
The Configuration registers control general global functionality that affects the entire device.
5.6.1 CONFIGURATION - 20H
Bit 7 - TIMEOUT - Enables the timeout and idle functionality of the SMBus protocol.
• ‘0’ (default) - The SMBus timeout and idle functionality are disabled. The SMBus interface will not time out if the
clock line is held low. Likewise, it will not reset if both the data and clock lines are held high for longer than 200us.
• ‘1’ - The SMBus timeout and idle functionality are enabled. The SMBus interface will reset if the clock line is held
low for longer than 30ms. Likewise, it will reset if both the data and clock lines are held high for longer than 200us.
Bit 5 - DIS_DIG_NOISE - Determines whether the digital noise threshold (see Section 5.19, "Sensor Input Noise Thresh-
old Register") is used by the device. Setting this bit disables the feature.
• ‘0’ - The digital noise threshold is used. If a delta count value exceeds the noise threshold but does not exceed the
touch threshold, the sample is discarded and not used for the automatic recalibration routine.
• ‘1’ (default) - The noise threshold is disabled. Any delta count that is less than the touch threshold is used for the
automatic recalibration routine.
Bit 4 - DIS_ANA_NOISE - Determines whether the analog noise filter is enabled. Setting this bit disables the feature.
• ‘0’ (default) - If low frequency noise is detected by the analog block, the delta count on the corresponding channel
is set to 0. Note that this does not require that Noise Status bits be set.
• ‘1’ - A touch is not blocked even if low frequency noise is detected.
Bit 3 - MAX_DUR_EN - Determines whether the maximum duration recalibration is enabled.
• ‘0’ (default) - The maximum duration recalibration functionality is disabled. A touch may be held indefinitely and no
recalibration will be performed on any sensor input.
• ‘1’ - The maximum duration recalibration functionality is enabled. If a touch is held for longer than the MAX_DUR
bit settings (see Section 5.8), the recalibration routine will be restarted (see Section 4.4.3, "Delayed Recalibra-
tion").
5.6.2 CONFIGURATION 2 - 44H
Bit 6 - BC_OUT_RECAL - Controls whether to retry analog calibration when the base count is out of limit for one or more
sensor inputs.
• ‘0’ - When the BC_OUTx bit is set for a sensor input, the out of limit base count will be used for the sensor input.
• ‘1’ (default) - When the BC_OUTx bit is set for a sensor input (see Section 5.16, "Base Count Out of Limit Regis-
ter"), analog calibration will be repeated on the sensor input.
Bit 5 - BLK_PWR_CTRL - Determines whether the device will reduce power consumption while waiting between con-
version time completion and the end of the sensing cycle.
• ‘0’ (default) - The device will reduce power consumption during the time between the end of the last conversion
and the end of the sensing cycle.
• ‘1’ - The device will not reduce power consumption during the time between the end of the last conversion and the
end of the sensing cycle.
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DS00001570C-page 29