MC68HC908LB8_05 Datasheet, PDF (116/234 Pages) Freescale Semiconductor, Inc – M68HC08 Microcontrollers

Low-Power Modes
11.10 Op Amp/Comparator
11.10.1 Wait Mode
While in WAIT the state of the op amp/comparator cannot be changed. If the op amp/comparator module
is not needed during wait mode, reduce power consumption by disabling the op amp/comparator before
executing the WAIT command.
11.10.2 Stop Mode
The op amp/comparator is inactive after execution of the STOP command. The op amp/comparator will
be in a low-power state and will not drive its output pin. When the MCU exits stop mode after and external
interrupt, the op amp/comparator continues operation.
11.11 Oscillator Module (OSC)
11.11.1 Wait Mode
The WAIT instruction has no effect on the oscillator logic. BUSCLKX2 and BUSCLKX4 continue to drive
to the SIM module.
11.11.2 Stop Mode
The STOP instruction disables either the XTALCLK, the RCCLK, or INTCLK output, hence BUSCLKX2
and BUSCLKX4.
11.12 Pulse-Width Modulator Module (PWM)
11.12.1 Wait Mode
When the microcontroller is put in low-power wait mode via the WAIT instruction, all clocks to the PWM
module will continue to run. If an interrupt is issued from the PWM module (via a reload or a fault), the
microcontroller will exit wait mode.
Clearing the PWMEN bit before entering wait mode will reduce power consumption in wait mode because
the counter, prescaler divider, and LDFQ divider will no longer be clocked. In addition, power will be
reduced because the PWMs will no longer toggle.
11.12.2 Stop Mode
When the microcontroller is put into stop mode via the STOP instruction, the PWM will stop functioning.
The PWM0 and PWM1 outputs are set to logic 0. The STOP instruction does not affect the register
conditions or the state of the PWM counters. When the MCU exits stop mode after an external interrupt
the PWM resumes operation.
MC68HC908LB8 Data Sheet, Rev. 1
116
Freescale Semiconductor