K60P100M100SF2RM Datasheet, PDF (1761/1809 Pages) Freescale Semiconductor, Inc – K60 Sub-Family Reference Manual

Chapter 55 Touch sense input (TSI)
55.4.3 TSI low power mode
The TSI module enters low power mode if the GENCS[STPE] is set to one and the MCU
is programmed into one of the following operational modes: LLS, VLLS1, VLLS2 or
VLLS3. In low power mode, only one selectable pin is active, being able to perform
capacitance measurements. The scan period is defined by GENCS[LPSCNITV]. Two low
power clock sources are available in the TSI low power mode, LPOCLK and
VLPOSCCLK, being selected by the GENCS[LPCLKS].
In low power mode the TSI interrupt can also be configured as end-of-scan or out-of-
range and the GENCS[TSIIEN] must be set in order to generate these interrupts. The TSI
interrupt causes the exit of the low power mode, entrance into the active mode, and the
MCU wake up.
In low power mode the electrode scan unit is always configured to periodical low power
scan.
55.4.4 Block diagram
The following figure shows the block diagram of TSI module.
Capacitance Measurement Unit
CAPTRM REFCHRG DELVOL
PAD0
PAD1
PAD15
EXTCHRG DELVOL
PS ^{TSI Reference Oscillator}
TSI
Electrode
Oscillator
Prescaler
Counter
Modulo
Control
16-bit
Counter
TSICHnCNT
NSCN
STM STPE SMOD LPSCNITV
Scan
Trigger
Channel
Polling
FSM
EOSF
Low
Power
Scan
Control
MCGIRCLK
OSCERCLK
BUS CLK
LLS/VLLSx
Modes
2 Windowed
Comparators
Touch and
Error
Detection
OVRF
PEN[15:0]
LPOCLK VLPOSCCLK ^{TSICHnHTH TSICHnLTH}
overrun interrupt
end of scan interrupt
Touch Detection Unit
Electrode Scan Unit
Figure 55-3. TSI block diagram
Error Interrupt
EXTERF
OUTRGF
out of range
interrupt
K60 Sub-Family Reference Manual, Rev. 6, Nov 2011
Freescale Semiconductor, Inc.
1761