MC68HC708MP16 Datasheet, PDF (365/398 Pages) Freescale Semiconductor, Inc – Microcontrollers

Technical Data — MC68HC708MP16
Section 20. Power-On Reset (POR)
20.1 Contents
20.2 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 365
20.3 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .365
20.2 Introduction
This section describes the power-on reset (POR) module (Version B).
20.3 Functional Description
The POR module provides a known, stable signal to the MCU at power-
on. This signal tracks V_DD 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. V_DD at the POR must go completely to zero to reset
the MCU. To detect power-loss conditions, use a low voltage inhibit
module (LVI) or other suitable circuit. Inputs to the POR_B00 are
SIMINIT and SECZDET from the SIM and EPROM security circuits,
respectively.
MC68HC708MP16 — Rev. 3.1
Freescale Semiconductor
Power-On Reset (POR)
Technical Data
365