HC805K3GRSSLASHD datasheet(49/119 Pages) NXP

49 / 119 page

MC68HC805K3 — Rev. 1.0

Resets

General Release Specification — MC68HC805K3

Section 5. Resets

5.1 Contents

5.2

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .49

5.3

External Reset (RESET). . . . . . . . . . . . . . . . . . . . . . . . . . . . . .50

5.4

Internal Resets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .50

5.4.1

Power-On Reset (POR). . . . . . . . . . . . . . . . . . . . . . . . . . . .50

5.4.2

Computer Operating Properly Reset (COPR) . . . . . . . . . . .51

5.4.3

Illegal Address Reset (ILADR) . . . . . . . . . . . . . . . . . . . . . .51

5.2 Introduction

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 Figure 5-1. All the internal peripheral modules that

drive external pins are reset by the synchronous reset signal (RST)

coming from a latch, which is synchronized to the PH2 bus clock and set

by any of the four reset sources.

NOTE:

Activation of the RST signal generally is referred to as a reset of the

device, unless otherwise specified.

Freescale Semiconductor, Inc.

For More Information On This Product,

Go to: www.freescale.com

HC805K3GRS/D Datasheet(PDF) 49 Page - NXP Semiconductors