Information

• End-of-scan or out-of-range interrupt
• TSI error interrupts: pad short to V
DD
/V
SS
or conversion overrun
• Automatically compensates for temperature and supply voltage variations within
operating parameters
• Stand alone operation not requiring any external crystal even in low-power modes
• Configurable integration of each electrode capacitance measurement from 1 to 4096
periods
• Programmable Electrode Oscillator and TSI Reference Oscillator allowing high
sensitivity, small scan time, and low-power functionality.
• Uses only one pin per electrode implementation with no external hardware required
51.3 Overview
This section presents an overview of the TSI module. The following figure presents the
simplified TSI module block diagram.
External
Electrodes
Cap Switch
PAD0
PAD1
PAD15
Capacitance Measurement Unit
NSCN PS EXTCHRG REFCHRG
TSICHnCNT
STPE
STM
Electrode
Scan Unit
EOSF
PEN [15:0]
OVRF
SMOD
LPSCNITV
Touch
Detection
Unit
TSICHLTH
TSICHHTH
EXTERF
OUTRGF
Touch Sensing Input (TSI) Module
Figure 51-1. TSI block diagram
Overview
K20 Sub-Family Reference Manual, Rev. 1.1, Dec 2012
1412
Preliminary
Freescale Semiconductor, Inc.
General Business Information