MC68HC705J1ACPE Datasheet, PDF (81/162 Pages) Freescale Semiconductor, Inc – Freescale Semiconductor, Inc.

Freescale Semiconductor, Inc.
Low-Power Modes
Effects of Stop and Wait Modes
• COP watchdog reset — A timeout of the COP watchdog resets the
MCU, starts the CPU clock, and loads the program counter with
the contents of locations $07FE and $07FF. Software can enable
timer interrupts so that the MCU periodically can exit wait mode to
reset the COP watchdog.
• Timer interrupt — Real-time interrupt requests and timer overflow
interrupt requests start the MCU clock and load the program
counter with the contents of locations $07F8 and $07F9.
5.4 Effects of Stop and Wait Modes
The STOP and WAIT instructions have the effects described in this
subsection on MCU modules.
5.4.1 Clock Generation
The STOP instruction:
The STOP instruction disables the internal oscillator, stopping the
CPU clock and all peripheral clocks.
After exiting stop mode, the CPU clock and all enabled peripheral
clocks begin running after the oscillator stabilization delay.
NOTE: The oscillator stabilization delay holds the MCU in reset for the first 4064
internal clock cycles.
The WAIT instruction:
The WAIT instruction disables the CPU clock.
After exiting wait mode, the CPU clock and all enabled peripheral
clocks immediately begin running.
MC68HC705J1A — Rev. 4.0
Low-Power Modes
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Technical Data