MC68HC05P18 Datasheet, PDF (59/144 Pages) Freescale Semiconductor, Inc – Advance Information

Freescale Semiconductor, Inc.
Operating Modes
STOP Instruction
6.5 STOP Instruction
The STOP instruction can result in one of two modes of operation
depending on the option programmed in the mask option register 1. If the
stop conversion to halt option (MOR1, bit 5) is not chosen, the STOP
instruction will behave like a normal STOP instruction in the M68HC805
Family and place the MCU in stop mode. If the stop conversion to halt
option is chosen, the STOP instruction will behave like a WAIT
instruction (with the exception of a brief delay at startup) and place the
MCU in halt mode.
6.5.1 Stop Mode
Execution of the STOP instruction (without conversion to halt) places the
MCU in its lowest power-consumption mode. In stop mode, the internal
oscillator is turned off, stopping all internal processing including the COP
watchdog timer. The RC oscillator that feeds the EEPROM and the A/D
converter is also stopped. Execution of the STOP instruction
automatically clears the I bit in the condition code register so that the
IRQ external interrupt is enabled. All other registers and memory remain
unaltered. All input/output lines remain unchanged.
The MCU can be brought out of the stop mode only by an IRQ external
interrupt (or port A, if selected as an option in the MOR2) or an externally
generated reset. When exiting stop mode, the internal oscillator will
resume after a 4064 PH2 clock cycle oscillator stabilization delay.
NOTE:
Execution of the STOP instruction without conversion to halt (via MOR1)
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
changed to halt mode by programming the appropriate option in MOR1.
MC68HC(8)05P18 — Rev. 2.0
MOTOROLA
Operating Modes
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Advance Information
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