盛群半導體（Holtek）公司的HT98R068是雙向無線電應用專用SOC MCU。在音訊處理功能方面, 包括預加重/去加重，壓擴，可程序擾頻設定，DTMF 編譯碼，可程序選擇碼編譯碼 及亞音頻之CTCSS/DCS編解碼。在MCU資源方面, 16kx16 ROM、1K Bytes RAM、34 I/O、內建有8個通道的12位ADC，4個通道的8位DAC，休眠快速喚醒、高低雙頻系統(tǒng)操作切換、串行傳輸接口SPI與RTC等功能，可減少外圍零件、縮小PCB 尺寸及降低成本。主要是用于模擬無線電對講機產品如 FRS, MURS, GMRS等市場。本文介紹了HT98R068主要特性和典型應用電路圖。

The device is an ASSP MCU for analog two way radio applications such as FRS. This device contains an 8-bit MCU, Audio Processor, ADC, DAC as well as an Operational Amplifier for peripheral interfaces. Additionally there are external interrupt functions and 16K of OTP Program Memory and 1K of SRAM Data Memory for general MCU control application. The Internal Audio Processor supports various programmable functions. These functions include CTCSS/DCSS encoding/decoding, DTMF encoding/decoding, scramble/descramble, VOX, compandor and so on. By connecting to a suitable RF module, the device provides a cost effective and flexible audio RF solution. Applications should include products in the Leisure Radio application area such as General Mobile Radios, Personal Mobile Radios, Multiple User Radios etc.

HT98R068主要特性：

●●Operating voltage: 3V~5V

●●Up to 0.25μs instruction cycle with 16MHz system clock

●●OTP Program Memory:16K x 16

●●Data Memory: 1K x8

●●Up to 34 bidirectional I/O lines

●●Ocillator type: external 32768Hz crystal -- LXT

●●Internal PLL to generate the system clock

––Input reference clock : 32768Hz

––Output: 2.048MHz x4/x5/x6/x8 (optional)

●●Four operational modes: Normal, Slow, Idle, Sleep

●●Watchdog Timer function with WDT oscillator

●●Real Time Clock function

●●8 channel 12-bit A/D converter

●●4 channel 8-bit D/A converter

●●All instructions executed in one or two instruction cycles

●●Table read instructions

●●63 powerful instructions

●●Up to 10-level subroutine nesting

●●Bit manipulation instruction

●●Low voltage reset function

●●Low voltage detect function

●●SPI interface for external MCU control

●●Two 8-bit and signal 16-bit programmable Timer/Event Counter with overflow interrupt and prescaler

●●Programmable Frequency Divider -- PFD

●●PGA : 5bit Operational Amplifier Gain setup

●●Sub-tone processor

––CTCSS/DCS encode/decode

●●In-band-Tone processor

––DTMF encoder/decode

––Selective call encoder/decoder

––User defined tone encoder/decoder

●●Audio processor

––Pre-emphasis/De-emphasis

––Scrambler

––Compandor

––VOX

●●Package types: 48/64-pin LQFP

圖1。HT98R068方框圖

圖2。HT98R068典型應用電路圖
詳情請見：
http://datasheets.maxim-ic.com/en/ds/78M6612-EVM-1.pdf