Information

Table 48-1. TSI Module funtionality in MCU operation modes (continued)
MCU operation mode TSI clock sources TSI operation mode
when TSIEN = 1
Functional electrode
pins
Required STPE state
Stop LPOCLK, MSGIRCLK,
OSCERCLK
Active mode All 1
VLPRun LPOCLK, MSGIRCLK,
OSCERCLK
Active mode All Don’t care
VLPWait LPOCLK, MSGIRCLK,
OSCERCLK
Active mode All Don’t care
VLPStop LPOCLK MSGIRCLK,
OSCERCLK
Active mode All 1
LLS LPOCLK,
VLPOSCCLK
Low power mode Determined by
PEN[LPSP]
1
VLLS3 LPOCLK,
VLPOSCCLK
Low power mode Determined by
PEN[LPSP]
1
VLLS2 LPOCLK,
VLPOSCCLK
Low power mode Determined by
PEN[LPSP]
1
VLLS1 LPOCLK,
VLPOSCCLK
Low power mode Determined by
PEN[LPSP]
1
48.4.1 TSI disabled mode
When GENCS[TSIEN] is cleared, the TSI module is disabled, and does not perform any
functionally in any MCU operation mode.
48.4.2 TSI active mode
In active mode, the TSI module has its full functionality, being able to scan up to 16
electrodes. The TSI can be in active mode with the MCU in any of the following
operational modes: run, wait, stop, VLPR, VLPW and VLPS.
Three clocks sources can be selected for the TSI module in active mode: LPOCLK,
MCGIRCLK and OSCERCLK.
48.4.3 TSI low power mode
The TSI modules enters in low power mode if the GENCS[STPE] is set to one and the
MCU enters in one of the following operational modes: LLS, VLLS1, VLLS2 and
VLLS3. In low power mode, only one selectable pin is active, being able to perform
Chapter 48 Touch sense input (TSI)
K20 Sub-Family Reference Manual, Rev. 2, Feb 2012
Freescale Semiconductor, Inc. 1191