MC68HC705P9 Datasheet, PDF (65/156 Pages) Motorola, Inc – HCMOS Microcontroller Unit

Contents
Stop Mode
1-mc68hc705p9
MOTOROLA
Low-Power Modes
Stop Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .65
Wait Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .68
Data-Retention Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .70
The STOP instruction puts the MCU in its lowest power-consumption
mode and has the following effects on the MCU:
• Stops the internal oscillator, the CPU clock, and the internal clock,
turning off the capture/compare timer, the COP watchdog, the
SIOP, and the ADC
• Clears the I bit in the condition code register, enabling external
interrupts
• Clears the ICIE, OCIE, and TOIE bits in the timer control register,
disabling further timer interrupts
The STOP instruction does not affect any other registers or any I/O lines.
The following events bring the MCU out of stop mode:
• An external interrupt signal on the IRQ/V_PP pin — A high-to-low
transition on the IRQ/V_PP pin loads the program counter with the
contents of locations $1FFA and $1FFB. The timer resumes
counting from the last value before the STOP instruction.
• External reset — A logic zero on the RESET pin resets the MCU
and loads the program counter with the contents of locations
$1FFE and $1FFF. The timer begins counting from $FFFC.
Low-Power Modes
65