MC68HC705P9 Datasheet, PDF (79/160 Pages) Motorola, Inc – HCMOS Microcontroller Unit

Freescale Semiconductor, Inc.
Low Power Modes
Wait Mode
Figure 6-3 shows the sequence of events caused by the WAIT
instruction.
WAIT
CLEAR I BIT IN CCR
STOP CPU CLOCK
NO
RESET?
YES
EXTERNAL
INTERRUPT?
NO
YES
TIMER
INTERRUPT?
NO
YES
OTHER ON-CHIP
INTERRUPT
SOURCES?
NO
RESTART CPU CLOCK
(1) FETCH RESET VECTOR
OR
(2) SERVICE INTERRUPT
a. SAVE CPU REGISTERS ON STACK
b. SET I BIT IN CCR
c. VECTOR TO INTERRUPT SERVICE ROUTINE
Figure 6-3. WAIT Instruction Flowchart
MC68HC705P9 — Rev. 4.0
MOTOROLA
Low Power Modes
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Technical Data
79