CRTOUCH Datasheet, PDF (50/68 Pages) Freescale Semiconductor, Inc – Capacitive and Resistive Touch Sensing Application Specific IC.

Memory Map and Registers Description
Signal
Description
7–0
Number of steps reported when a slide is perform side to side of the touch screen
RTSLDSTEPS
4.2.4 Calibration Values registers
This set of registers hold the calibration coefficients for the X and Y single touch coordinates, as well as the constants for each
axis required for two touch gesture calculations. Writing to these values calibrates the device without the need for touching the
calibration points on the screen. All of the values must be written to calibrate the device. The Status Register 2 bit for calibration
is set after a reset.
4.2.4.1 X calibration values
This set of three 16-bit values represents the calibration coefficients for the X coordinate. To obtain the X coordinate, the first
value is multiplied by the X sample, the second value by the Y sample, and the third value added with the products.
Bit
15
Field
14
13 12 11 10 9
8
7 65 4 3 2 1
0
XCALxMSB
XCALxLSB
Signal
15–8
XCALxMSB
7–0
XCALxLSB
Description
Most significant byte for the X coordinate calibration value.
Least significant byte for the X coordinate calibration value.
4.2.4.2 Y calibration values
This set of three 16-bit values represents the calibration coefficients for the Y coordinate. To obtain the Y coordinate, the first
value is multiplied by the X sample, the second value by the Y sample and the third value added with the products.
Bit
15
Field
14
13 12 11 10 9
8
7 65 4 3 2 1
0
XCALxMSB
XCALxLSB
Signal
15–8
YCALxMSB
7–0
YCALxLSB
Description
Most significant byte for theY coordinate calibration value.
Least significant byte for the Y coordinate calibration value.
CRTouch Data Sheet, Rev. 3
50
Freescale Semiconductor