Holtek HT95R25八位电话机微控制器应用方案

　　Holtek (盛群半导体)公司的HT95R25是八位电话机微控制器, 具有高集成度、低成本、低耗电和高效能等特性,有16K×16b ROM 2112B RAM和52个I/O,8级堆栈,内建两个16位计时器、一个RTC 计时器及外部中断触发等功能。HT95R25特别适合应用于通讯相关产品，例如多功能电话、无线电话、录音机、家庭安防等。本文介绍了HT95R25主要特性,方框图以及典型应用电路。

　　HT95R24、HT95R25为盛群半导体新开发的八位电话通信产品微控制器系列，具有ROM分别为8K×16 bits及16K×16 bits、RAM为2112 bytes、I/O分别为36及52埠、Stack 数目为8-level、内建两个16-bit Timer、一个RTC Timer及外部中断触发等功能，在封装方面则提供48 SSOP及64 LQFP的封装型式。利用内建PFD (Programmable Frequency Divider)可产生多种频率变化，搭配发声组件就可产生美妙的音乐，或是应用于红外线传输的载波讯号。

　　HT95R24、HT95R25内建拨号所需DTMF Generator，特别适合应用于通讯相关产品，例如多功能电话、无线电话、录音机、家庭安防等。目前家庭安防越来越受到重视，利用此系列产品，搭配软硬件控制，可以很容易做到家庭防盗检测及自动拨号的功能，提供使用者一个具有优异性价比的电话通信相关产品解决方案。

　　HT95R24、HT95R25的特点在于高整合性、低成本、低耗电、高效能，具有如同盛群其它8-bit MCU的高抗噪声特性、看门狗(Watchdog)的功能用以加强MCU防当机能力。盛群半导体同时提供软硬件功能齐全的发展系统HT-IDE3000，包含有实时仿真、内存∕缓存器存取、硬件断点逻辑设定、执行追踪分析等等功能，适合需要更快速并更具效率来发展程序及除错的使用者进行产品开发。

　　The HT95R25 MCU is an 8-bit high performance, RISC architecture microcontroller device specially designed for telephone applications. Device flexibility is enhanced with their internal special features such as power-down and wake-up functions, DTMF generator, PFD driver, etc. These features combine to ensure applications require a minimum of external components and therefore reduce overall product costs.

　　Having the advantages of low-power consumption, high-performance, I/O flexibility as well as low-cost, these devices have the versatility to suit a wide range of application possibilities such as deluxe feature phone, cordless phones, fax and answering machines, etc.

　　The device is best suited for phone products that comply with versatile dialer specification requirements for different areas or countries. The device is fully supported by the Holtek range of fully functional development and programming tools, providing a means for fast and efficient product development cycles.

　　HT95R25主要特性:

　　Operating voltage at fSYS= 3.58MHz: 2.2V~5.5V

　　16K_16 OTP type Program Memory

　　2112_8 Data Memory

　　50 bidirectional I/Os with pull-high options

　　2 NMOS output-only lines

　　External interrupt input

　　Dual 16-bit timers with interrupts

　　Timer external input

　　8-level stack

　　32768Hz system oscillator

　　32768Hz to 3.58MHz frequency-up PLL circuit

　　Real time clock function

　　Watchdog timer function

　　PFD driver output

　　DTMF generator

　　Power-down and wake-up feature for power-saving operation: Idle mode, Sleep mode, Green mode and normal mode

　　Up to 1.117_s instruction cycle with 3.58MHz system clock at VDD=2.2V~5.5V

　　Bit manipulation instructions

　　Table read function

　　63 powerful instructions

　　All instructions executed in 1 or 2 machine cycles

　　Supported by comprehensive suite of hardware and software tools

　　48-pin SSOP package　

　　图1.HT95R25方框图

　　图2.HT95R25应用电路图