MC68HC908MR16/MC68HC908MR32 — Rev. 4.0 Advance Information
MOTOROLA Power-On Reset (POR) 357
Advance Information — MC68HC908MR16/MC68HC908MR32
Section 20. Power-On Reset (POR)

20.1 Contents

20.2 Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .357
20.3 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .357

20.2 Introduction

This section describes the power-on reset (POR) module.

20.3 Functional Description

The POR module provides a known, stable signal to the microcontrolle r
unit (MCU) at power-on. This signal tracks VDD until the MCU generates
a feedback signal to indicate that it is properly initialized. At this time, the
POR drives its output low.
The POR is not a brown-out detector, low-voltage detector, or glitch
detector. VDD at the POR must go completely to 0 to reset the MCU. To
detect power-loss conditions, use a low-voltage inhibit module (LVI) or
other suitable circuit.