基于HT95R45设计的多功能电话MCU控制技术

HT95R45是8位电话通信产品微控制器, 具有4K、8K或16K 字 ROM、1152或2112 字节RAM, 内建二或三个16位定时器、一个RTC定时器及四个外部中断触发等功能, 非常适合带语音功能通讯产品的应用如多功能电话、无线电话、录音机、家庭安防等。本文介绍了HT95R45主要特性,方框图, PA输入/输出端口框图, PC,PD和PE输入/输出端口框图以及16位定时器/事件计数器0与1的结构框图, SPI和I2C方框图, DTMF接收器单端输入应用电路图.

The phone MCU is a 8-bit high performance, RISC architecture microcontroller devices specially designed for telephone applications. Devices flexibility are enhanced with their internal special features such as power-down and wake-up functions, DTMF generator,DTMF receiver, CPT detector, PFD driver, SPI and I2C interface, audio DAC output, 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 DTMF mode Caller ID phone, Home Security products, deluxe feature phones, cordless phones, fax and answering machines, etc.

The call progress tone detector is for Auto-dialing system use. Switched capacitors technology is implemented into the chip to get good performance characteristics of band pass filter in the range of 305Hz to 640Hz call progress tone which is dual tone multi-frequency signal. When it detected CPT signal then it generates relative envelopes for external microcontroller decision to finish different kinds of CPT signal detection such as dial tone, busy tone, ring-back tone and reorder tone.

The device will be ideally 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.

HT95R45主要特性:

_ Operating voltage:

fSYS=3.58MHz: 2.2V~5.5V

fSYS=7.16MHz: 3.0V~5.5V

fSYS=10.74MHz: 3.0V~5.5V

fSYS=14.32MHz: 4.5V~5.5V

_ Program Memory: 16K_16

_ 2112_8 Data Memory

_ 42 bidirectional I/Os with pull-high options

_ 2 NMOS output-only lines

_ External interrupt input

_ Three 16-bit timers with interrupts

_ Timer external input

_ 8-level stack

_ 32768Hz system oscillator

_ 32768Hz up to 14.32MHz frequency-up circuit

_ Real time clock function

_ Watchdog timer function

_ PFD driver output

_ Serial Interfaces Module: SIM for SPI or I2C

_ Internal DTMF generator

_ Internal DTMF receiver

_ 12-bit Audio DAC output

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

_ Up to 0.28_s instruction cycle with 14.32MHz system clock at VDD=4.5V~5.5V

_ Bit manipulation instructions

_ Table read function

_ 63 powerful instructions

_ All instructions executed in 1 or 2 machine cycles

_ Low voltage reset function

_ Supported by comprehensive suite of hardware and software tools

_ Internal Call Progress Tone (CPT) detector

_ 64/80-pin LQFP package


图1.HT95R45方框图

图2.HT95R45 PA输入/输出端口框图

图3.HT95R45 PC,PD和PE输入/输出端口框图

图4.HT95R45 16位定时器/事件计数器0结构框图

图5.HT95R45 16位定时器/事件计数器1结构框图

图6.HT95R45 SPI方框图


图7.HT95R45 I2C方框图

图8.HT95R45 DTMF接收器单端输入应用电路图