mc68hc05ct4fn Freescale Semiconductor, Inc, mc68hc05ct4fn Datasheet - Page 43

• Manufacturer Part Number: mc68hc05ct4fn
• Description: Mc68hc05 Family Of Microcontrollers Mcus
• Manufacturer: Freescale Semiconductor, Inc

General Release Specification — MC68HC05CT4
5.1 Contents
5.2 Introduction
5.3 External Reset (RESET)
MC68HC05CT4
—
Rev. 2.0
5.2
5.3
5.4
5.4.1
5.4.2
5.4.2.1
5.4.2.2
5.4.2.3
5.4.2.4
5.4.2.5
5.4.3
The MCU can be reset from four sources: one external input and three
internal restart conditions. The RESET pin is an input with a Schmitt
trigger as shown in
reset by the internal reset signal (RST). Refer to
timing detail.
The RESET pin is the only external source of a reset. This pin is
connected to a Schmitt trigger input gate to provide an upper and lower
threshold voltage separated by a minimum amount of hysteresis. This
external reset occurs whenever the RESET pin is pulled below the lower
threshold and remains in reset until the RESET pin rises above the
upper threshold. This active-low input will generate the RST signal and
Freescale Semiconductor, Inc.
For More Information On This Product,
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .43
External Reset (RESET). . . . . . . . . . . . . . . . . . . . . . . . . . . . . .43
Internal Resets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .46
Power-On Reset (POR). . . . . . . . . . . . . . . . . . . . . . . . . . . .46
Computer Operating Properly Reset (COPR) . . . . . . . . . . .46
Illegal Address. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .48
Resetting the COP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .46
COP During Wait Mode . . . . . . . . . . . . . . . . . . . . . . . . . .47
COP During Stop Mode . . . . . . . . . . . . . . . . . . . . . . . . . .47
COP Watchdog Timer Considerations . . . . . . . . . . . . . . .47
COP Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .48
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Figure
Resets
5-1. All the internal peripheral modules will be
Section 5. Resets
General Release Specification
Figure 5-2
for reset