Freescale 公司的MCF51EM256/128系列是ColdFire DISC 32位微控制器(MCU),是基于V1 ColdFire核的系統級芯片(SoC),3.6V時的工作頻率高達50.33MHz,有多達256KB的閃存,多達16KB的RAM,電池工作模式的功耗小于1.3uA,通信接口包括UART,IIC 和SPI, 目標應用為智能測試,相位測量單元,工業能量測量和1相與3相電表等.本文介紹MCF51EM256/128系列主要特性,功能方框圖,以及基于MCF51EM256的多相智能電表參考設計的方框圖,主要特性和指標和詳細電路圖.

The MCF51EM256/128 series microcontrollers are a member of the ColdFire? family of reduced instruction set computing (RISC) microprocessors.

This document provides an overview of these 32-bit microcontrollers, focusing on their highly integrated and diverse feature set.

These microcontrollers are systems-on-chips (SoCs) that are based on the V1 ColdFire core and the following features:

? Operating at processor core speeds up to 50.33 MHz (peripherals operate at half of
this speed) at 3.6 V to 2.5 V and 20 MHz at 2.5 V to 1.8 V

? Up to 256 KB of flash memory

? Up to 16 KB of RAM

? Less than 1.3 μA of typical power consumption in battery mode, with MCU supply off

? Ultra-low power independent RTC with calendar features, separate time base, power domain, and 32 bytes of RAM

? A collection of communications peripherals, including UART, IIC and SPI

? Integrated 16-bit SAR analog-to-digital converter

? Programmable delay block (PDB)

? Two analog comparators with selectable interrupt (PRACMP)

? LCD driver

? Three serial communications interface modules (SCI)

? Three serial peripheral interfaces

? Inter-integrated circuit (IIC)

? Two 8-bit and one 16-bit modulo timers (MTIM)

? Two-channel timer/PWM module (TPM)

MCF51EM256目標應用:

Smart Metering

Sensor collect

Phase Measurement Units

Industrial energy measurement

1- phase & 3- phase electricity meters


圖1.MCF51EM256系列方框圖

基于MCF51EM256的多相智能電表參考設計

The polyphase reference design is a cost-optimized implementation of a 1-phase or 3-phase 110V and 230V smart electricity meter. The reference design contains all of the necessary hardware and software to make the development of production smart meters quick and easy, including pre-compliance test data is to help with the certification process. It is based on the MCF51EM256 ColdFire? MCU and is designed to meet US ANSI C12, Euro/Asia IEC62053 standards up to and beyond class 0.5

多相智能電表參考設計主要特性:

Complete solution for 1-phase, 3-phase, 110V and 230V electricity meters for all global regions

Able to achieve class 0.5 or better for active energy

Enables rapid development and deployment of a production meter

Full documentation including pre-compliance test data is available, to simplify and speed certification process

Software source code is supplied as a CodeWarrior project for easy re-use:

Direct use in a metering application

Customization and extension

Use of individual modules in other projects

Full working reference design is available for loan and evaluation

Designed and tested against:

IEC 62053-22 International Energy Metering Specification, class 0.5 (or better) for active energy

IEC 62053-23 International Energy Metering Specification, class 2 for reactive energy

IEC 62056-21 International Energy Metering data exchange Specification

IEC 62053-22, IEC 62053-23, IEC 62052-11 Electro Static Discharge (ESD), tested per IEC 61000-4


圖2.多相智能電表參考設計方框圖

基于MCF51EM256的多相智能電表(220V)指標:

MCF51EM256-based Poly Phase Energy Meter Reference Design 220V Technical Specifications

Environmental

Compliance IEC 60529

Ingress protection IP 51 (Indoor type meter)

Operating Temperature -25℃ to +55℃

Storage Temperature -25℃ to +70℃

Humidity 95%



基于MCF51EM256的多相智能電表主要特性:




圖3.基于MCF51EM256的多相智能電表外形圖

圖4.多相智能電表參考設計電路圖(1)

圖5.多相智能電表參考設計電路圖(2)

圖6.多相智能電表參考設計電路圖(3)

圖7.多相智能電表參考設計電路圖(4)

圖8.多相智能電表參考設計電路圖(5)

圖9.多相智能電表參考設計電路圖(6)

圖10.多相智能電表參考設計電路圖(7)

圖11.多相智能電表參考設計電路圖(8)

圖12.多相智能電表參考設計電路圖(9)