MC68HC908GZ8 Datasheet, PDF (46/344 Pages) Motorola, Inc – Microcontrollers

Low-Power Modes
3.13.2 Stop Mode
The timebase module may remain active after execution of the STOP instruction if
the oscillator has been enabled to operate during stop mode through the
OSCENINSTOP bit in the CONFIG2 register. The timebase module can be used
in this mode to generate a periodic wakeup from stop mode.
If the oscillator has not been enabled to operate in stop mode, the timebase module
will not be active during stop mode. In stop mode, the timebase register is not
accessible by the CPU.
If the timebase functions are not required during stop mode, reduce the power
consumption by stopping the timebase before enabling the STOP instruction.
3.14 Timer Interface Module (TIM1 and TIM2)
3.14.1 Wait Mode
The timer interface modules (TIM) remain active in wait mode. Any enabled CPU
interrupt request from the TIM can bring the MCU out of wait mode.
If TIM functions are not required during wait mode, reduce power consumption by
stopping the TIM before executing the WAIT instruction.
3.14.2 Stop Mode
The TIM is inactive in stop mode. The STOP instruction does not affect register
states or the state of the TIM counter. TIM operation resumes when the MCU exits
stop mode after an external interrupt.
3.15 Exiting Wait Mode
These events restart the CPU clock and load the program counter with the reset
vector or with an interrupt vector:
• External reset — A logic 0 on the RST pin resets the MCU and loads the
program counter with the contents of locations $FFFE and $FFFF.
• External interrupt — A high-to-low transition on an external interrupt pin
(IRQ pin) loads the program counter with the contents of locations: $FFFA
and $FFFB; IRQ pin.
• Break interrupt — In emulation mode, a break interrupt loads the program
counter with the contents of $FFFC and $FFFD.
• Computer operating properly (COP) module reset — A timeout of the COP
counter resets the MCU and loads the program counter with the contents of
$FFFE and $FFFF.
Data Sheet
46
Low-Power Modes
MC68HC908GZ8
Freescale Semiconductor