MC68HC705C9A Datasheet, PDF (45/118 Pages) Motorola, Inc – Microcontrollers

Chapter 6
Low-Power Modes
6.1 Introduction
This section describes the low-power modes.
6.2 Stop Mode
The STOP instruction places the MCU in its lowest-power consumption mode. In stop mode, the internal
oscillator is turned off, halting all internal processing, including timer operation.
During the 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 to enable
external interrupts. All other registers and memory remain unaltered. All input/output lines remain
unchanged. The processor can be brought out of the stop mode only by an external interrupt or reset. See
Figure 6-1.
OSC1(1)
tRL
RESET
IRQ(2)
IRQ(3)
tLIH
tILCH
4064 tcyc
INTERNAL
CLOCK
INTERNAL
ADDRESS
BUS
Notes:
1. Represents the internal gating of the OSC1 pin
2. IRQ pin edge-sensitive mask option
3. IRQ pin level and edge-sensitive mask option
3FFE 3FFE 3FFE 3FFE 3FFF
RESET OR INTERRUPT
VECTOR FETCH
Figure 6-1. Stop Recovery Timing Diagram
MC68HC05C9A Advance Information Data Sheet, Rev. 4.1
Freescale Semiconductor
45