LVI Module Block Diagram | Freescale Semiconductor MC68HC908MR16

Chapter 9 Low-Voltage Inhibit (LVI)

9.1 Introduction

This section describes the low-voltage inhibit (LVI) module, which monitors the voltage on the VDD pin and can force a reset when the VDD voltage falls to the LVI trip voltage.

9.2 Features

Features of the LVI module include:

•Programmable LVI reset

•Programmable power consumption

•Digital filtering of VDD pin level

•Selectable LVI trip voltage

9.3 Functional Description

Figure 9-1shows the structure of the LVI module. The LVI is enabled out of reset. The LVI module contains a bandgap reference circuit and comparator. The LVI power bit, LVIPWR, enables the LVI to monitor VDD voltage. The LVI reset bit, LVIRST, enables the LVI module to generate a reset when VDD falls below a voltage, VLVRX, and remains at or below that level for nine or more consecutive CGMXCLK.

VLVRX and VLVHX are determined by the TRPSEL bit in the LVISCR (see Figure 9-2). LVIPWR and LVIRST are in the configuration register (CONFIG). See Chapter 5 Configuration Register (CONFIG).

VDD

LOW VDD

DETECTOR

TRPSEL

FROM LVISCR

LVIPWR

FROM CONFIG

CPU CLOCK

		VDD
VDD > LVItrip = 0		VDD
		DIGITAL FILTER
VDD < LVItrip = 1		DIGITAL FILTER




	ANLGTRIP

FROM CONFIG

LVIRST

LVIOUT

LVI RESET

Figure 9-1. LVI Module Block Diagram

MC68HC908MR32 • MC68HC908MR16 Data Sheet, Rev. 6.1

Freescale Semiconductor

MC68HC908MR16, MC68HC908MR32 specifications

Freescale Semiconductor's MC68HC908MR32 and MC68HC908MR16 microcontrollers are part of the popular HC08 family, designed primarily for embedded applications. These microcontrollers are particularly favored in automotive, industrial, and consumer product sectors due to their reliability and versatility.

One of the standout features of the MC68HC908MR series is its CMOS technology, which enhances performance while minimizing power consumption. This makes these microcontrollers suitable for battery-operated devices. They operate at a maximum clock frequency of 2 MHz and offer a 16-bit architecture, providing a solid balance between processing power and efficiency.

The MC68HC908MR32 variant is equipped with 32KB of flash memory, which allows for the storage of complex programs and extensive data handling. In contrast, the MC68HC908MR16 features 16KB of flash memory, making it ideal for simpler applications. Both microcontrollers also come with 1KB of RAM, enabling efficient data processing and real-time operations.

Another significant characteristic of these microcontrollers is their integrated peripherals. They come with multiple input/output (I/O) pins, which allow for connectivity with various sensors and actuators. The built-in timer systems offer precise timing control for automotive and industrial applications, while the Analog-to-Digital Converter (ADC) provides essential conversion capabilities for various analog signals.

For communication purposes, the MC68HC908MR series includes a serial communication interface, enabling easy integration with other devices and systems. This versatility facilitates the development of complex systems that require interaction with external components.

Security is another crucial aspect of these microcontrollers. They have built-in fail-safe mechanisms to ensure reliable operation under various conditions, making them suitable for critical systems. Additionally, their robust architecture helps to safeguard against potential disruptions or attacks.

In summary, Freescale Semiconductor's MC68HC908MR32 and MC68HC908MR16 microcontrollers are key players in the embedded systems landscape. Their blend of power efficiency, integrated features, and scalability ensures they remain relevant for a wide array of applications, making them a favored choice among engineers and developers looking for dependable solutions in a competitive market.

Freescale Semiconductor MC68HC908MR16 Chapter Low-Voltage Inhibit LVI, LVI Module Block Diagram

Models: MC68HC908MR16 MC68HC908MR32

Chapter 9

Low-Voltage Inhibit (LVI)