CAP1106

DS00001624B-page 28

 2015 Microchip Technology Inc.

Bits 1 - 0 - CYCLE_TIME[1:0] - Determines the overall cycle time for all measured channels during normal operation as

shown in Table 6-20. All measured channels are sampled at the beginning of the cycle time. If additional time is remain-

ing, then the device is placed into a lower power state for the remaining duration of the cycle.

APPLICATION NOTE: The programmed cycle time is only maintained if the total averaging time for all samples is

less than the programmed cycle. The AVG[2:0] bits will take priority so that if more samples

are required than would normally be allowed during the cycle time, the cycle time will be

extended as necessary to accommodate the number of samples to be measured.

6.11

Calibration Activate Register

The Calibration Activate register forces the respective sensor inputs to be re-calibrated affecting both the analog and

digital blocks. During the re-calibration routine, the sensor inputs will not detect a press for up to 600ms and the Sensor

Input Base Count register values will be invalid. During this time, any press on the corresponding sensor pads will inval-

idate the re-calibration. When finished, the CALX[9:0] bits will be updated (see Section 6.25).

When the corresponding bit is set, the device will perform the calibration and the bit will be automatically cleared once

the re-calibration routine has finished.

Bit 5 - CS6_CAL - When set, the CS6 input is re-calibrated. This bit is automatically cleared once the sensor input has

been re-calibrated successfully.

Bit 4 - CS5_CAL - When set, the CS5 input is re-calibrated. This bit is automatically cleared once the sensor input has

been re-calibrated successfully.

Bit 3 - CS4_CAL - When set, the CS4 input is re-calibrated. This bit is automatically cleared once the sensor input has

been re-calibrated successfully.

Bit 2 - CS3_CAL - When set, the CS3 input is re-calibrated. This bit is automatically cleared once the sensor input has

been re-calibrated successfully.

Bit 1 - CS2_CAL - When set, the CS2 input is re-calibrated. This bit is automatically cleared once the sensor input has

been re-calibrated successfully.

Bit 0 - CS1_CAL - When set, the CS1 input is re-calibrated. This bit is automatically cleared once the sensor input has

been re-calibrated successfully.

TABLE 6-19:

SAMP_TIME BIT DECODE

SAMP_TIME[1:0]

Sample Time

10

0

0

320us

0

1

640us

1

0

1.28ms (default)

1

1

2.56ms

TABLE 6-20:

CYCLE_TIME BIT DECODE

CYCLE_TIME[1:0]

Overall Cycle Time

10

00

35ms

0

1

70ms (default)

1

0

105ms

1

1

140ms

TABLE 6-21:

CALIBRATION ACTIVATE REGISTER

ADDR

R/W

Register

B7

B6

B5B4

B3B2B1

B0

Default

26h

R/W

Calibration

Activate

--

CS6_

CAL

CS5_

CAL

CS4_

CAL

CS3_

CAL

CS2_

CAL

CS1_

CAL

00h