CAP1208 datasheet(46/67 Pages) MICROCHIP

46 / 67 page

8-Channel Capacitive Touch Sensor

Datasheet

DS00001570B-page 46

 2014 Microchip Technology Inc.

Bit 1 - COMP_PTRN - Determines whether the MTP detection circuitry will use the Multiple Touch

Pattern register as a specific pattern of sensor inputs or as an absolute number of sensor inputs.



‘0’ (default) - The MTP detection circuitry will use the Multiple Touch Pattern register bit settings as

an absolute minimum number of sensor inputs that must be above the threshold or have Noise

Flag Status bits set. The number will be equal to the number of bits set in the register.



‘1’ - The MTP detection circuitry will use pattern recognition. Each bit set in the Multiple Touch

Pattern register indicates a specific sensor input that must have a delta count greater than the MTP

threshold or have a Noise Flag Status bit set. If the criteria are met, the MTP status bit will be set.

Bit 0 - MTP_ALERT - Enables an interrupt if an MTP event occurs. In either condition, the MTP status

bit will be set.



‘0’ (default) - If an MTP event occurs, the ALERT# pin is not asserted.



‘1’ - If an MTP event occurs, the ALERT# pin will be asserted.

5.16

Multiple Touch Pattern Register

The Multiple Touch Pattern register acts as a pattern to identify an expected sensor input profile for

diagnostics or other significant events. There are two methods for how the Multiple Touch Pattern

threshold or have Noise Flag Status bits set. Which method is used is based on the COMP_PTRN bit

(see Section 5.15). The methods are described below.

1. Specific Sensor Inputs: If, during a single sensing cycle, the specific sensor inputs above the MTP

threshold or with Noise Flag Status bits set match those bits set in the Multiple Touch Pattern

2. Number of Sensor Inputs: If, during a single sensing cycle, the number of sensor inputs with a delta

count above the MTP threshold or with Noise Flag Status bits set is equal to or greater than the

number of pattern bits set, an MTP event is flagged.

Table 5.26 MTP_TH Bit Decode

MTP_TH[1:0]

THRESHOLD DIVIDE SETTING

12.5% (default)

25%

37.5%

100%

Table 5.27 Multiple Touch Pattern Register

ADDR

R/W

DEFAULT

2Dh

R/W

Multiple

Touch

Pattern

CS8_

PTRN

CS7_

PTRN

CS6_

PTRN

CS5_

PTRN

CS4_

PTRN

CS3_

PTRN

CS2_

PTRN

CS1_

PTRN

FFh

CAP1208 Datasheet(PDF) 46 Page - Microchip Technology

CAP1208 Datasheet(HTML) 46 Page - Microchip Technology

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67

Datasheet Download

Link URL