MC68HC05V12 Datasheet, PDF (76/246 Pages) Freescale Semiconductor, Inc – HCMOS Microcontreller Unit

Freescale Semiconductor, Inc.
Low-Power Modes
6.4 Stop Mode
Execution of the STOP instruction with the mask option enabled places
the MCU in its lowest power-consumption mode. In stop mode, the
internal oscillator is turned off, halting all internal processing, including
the computer operating properly (COP) watchdog timer.
During stop mode, the TCR bits are altered to remove any pending timer
interrupt request and to disable any further timer interrupts. The timer
prescaler is cleared. The I bit in the CCR is cleared and the IRQE mask
is set in the ICSR to enable external interrupts. All other registers and
memory remain unaltered. All input/output lines remain unchanged.
The MCU can be brought out of stop mode only by:
• An IRQ pin external interrupt
• An externally generated reset
• A falling edge on any port C pin (if enabled)
• A rising edge on the BDLC RXP pin
When exiting the stop mode, the internal oscillator will resume after a
4064 internal processor clock cycle oscillator stabilization delay as
shown in Figure 6-1.
NOTE:
Entering stop mode will cause the oscillator to stop and, therefore,
disable the COP watchdog timer. If the COP watchdog timer is to be
used, stop mode should be disabled by disabling the mask option.
Technical Data
Low-Power Modes
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MC68HC05V12 — Rev. 2.0