Information

Chapter 51
Touch sense input (TSI)
51.1 Introduction
NOTE
For the chip-specific implementation details of this module's
instances see the chip configuration chapter.
The touch sensing input (TSI) module provides capacitive touch sensing detection with
high sensitivity and enhanced robustness. Each TSI pin implements the capacitive
measurement of an electrode having individual programmable detection thresholds and
result registers. The TSI module can be functional in several low-power modes with
ultra-low current adder and waking up the CPU in a touch event. It provides a solid
capacitive measurement module to the implementation of touch keypad, rotaries, and
sliders.
51.2 Features
TSI module features included:
• Support for as many as 16 input capacitive touch-sensing pins with individual result
registers
• Automatic detection of electrode capacitance change in low-power mode with
programmable upper and lower threshold
• Automatic periodic scan unit with different duty cycles for run and low-power modes
• Fully support with Freescale touch-sensing SW library suite the implementation of
keypads, rotaries and sliders
• Operation across all low-power modes: WAIT, STOP, VLPR, VLPW, VLPS, LLS,
VLLS3, VLLS2, VLLS1
• Capability to wake up MCU from low-power modes.
• Configurable interrupts:
K20 Sub-Family Reference Manual, Rev. 1.1, Dec 2012
Freescale Semiconductor, Inc.
Preliminary
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