MC68HC05C9E Datasheet, PDF (35/106 Pages) Freescale Semiconductor, Inc – Microcontrollers

Chapter 6
Low-Power Modes
6.1 Introduction
This section describes the low-power stop and wait modes.
6.2 Stop Mode
The STOP instruction places the microcontroller unit (MCU) in its lowest-power consumption mode. In
stop mode, the internal oscillator is turned off, halting all internal processing, including timer operation.
During 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 condition code register (CCR)
is cleared to enable external interrupts. All other registers and memory remain unaltered. All input/output
(I/O) lines remain unchanged. The processor can be brought out of 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
$3FFE
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 $3FFF
RESET OR INTERRUPT
VECTOR FETCH
Figure 6-1. Stop Recovery Timing Diagram
MC68HC05C9E Advance Information Data Sheet, Rev. 0.1
Freescale Semiconductor
35