K60P100M100SF2RM Datasheet, PDF (1758/1809 Pages) Freescale Semiconductor, Inc – K60 Sub-Family Reference Manual

Overview
• Configurable integration of each electrode capacitance measurement from 1 to 4096
times
• Programmable electrode oscillator and TSI Reference Oscillator for high sensitivity,
small scan time and low power functionality
• Only uses one pin per electrode implementation with no external hardware required
55.3 Overview
This section presents an overview of the TSI module. The following figure presents the
simplified TSI module block diagram.
External
Electrodes
PAD0
Touch Sensing Input (TSI) Module
NSCN PS EXTCHRG DELVOL REFCHRG
PAD1
Capacitance Measurement Unit
TSICHnCNT
PAD15
STPE STM
Electrode
Scan Unit
EOSF
LPSCNITV
SMOD
OVRF
PEN [15:0]
Touch
Detection
Unit
EXTERF
OUTRGF
TSICHnLTH TSICHnHTH
Figure 55-1. Touch sensing input block diagram
55.3.1 Electrode capacitance measurement unit
The electrode capacitance measurement unit senses the capacitance of a TSI pin and
outputs a 16-bit result. This module is based in dual oscillator architecture. One oscillator
is connected to the external electrode array and oscillates according to the electrode
1758
K60 Sub-Family Reference Manual, Rev. 6, Nov 2011
Freescale Semiconductor, Inc.