·ITU-T G.729的一個實現例子(包括附錄b的vod檢測等功能)-ITU-T g.729 example, include VOD detect of reference B, etc.文件列表(點擊判斷是否您需要的文件): g729b_v14 .........\acelp_co.c .........\basic_op.c .....
電子、電氣產品的設計,必須保證在一定的電磁環境中能正常工作,既滿足標準規定的抗干擾極限值要求,在受到一定的電磁干擾時,無性能降級或故障;又要滿足標準規定的電磁輻射極限值的要求,對電磁環境不構成污染。所以,產品設計之初,就要從分析產品預期的電磁環境、干擾源、耦合途徑和敏感部件入手,采用相應的技術措施,抑制干擾源、切斷或削弱耦合途徑,增強敏感部件的抗干擾能力等。文中詳細介紹了一款485通訊隔離產品從輻射超標到順利通過FCC CLASS B認證,在原理設計、PCB制板等多方面所做的各項改進措施。文中所提到的方法及規則,對產品EMC設計具有很大的參考及指導意義。
針對目前使用的RS232接口數字化B超鍵盤存在PC主機啟動時不能設置BIOS,提出一種PS2鍵盤的設計方法?;赪78E052D單片機,采用8通道串行A/D轉換器設計了8個TGC電位器信息采集電路,電位器位置信息以鍵盤掃描碼序列形式發送,正交編碼器信號通過XC9536XL轉換為單片機可接收的中斷信號,軟件接收到中斷信息后等效處理成按鍵。結果表明,在滿足開機可設置BIOS同時,又可實現超聲特有功能,不需要專門設計驅動程序,接口簡單,成本低。
Abstract: Aiming at the problem of the digital ultrasonic diagnostic imaging system keyboard with RS232 interface currently used couldn?蒺t set the BIOS when the PC boot, this paper proposed a design method of PS2 keyboards. Based on W78E052D microcontroller,designed eight TGC potentiometers information acquisition circuit with 8-channel serial A/D converter, potentiometer position information sent out with keyboard scan code sequentially.The control circuit based on XC9536 CPLD is used for converting the mechanical actions of the encoders into the signals that can be identified by the MCU, software received interrupt information and equivalently treatmented as key. The results show that the BIOS can be set to meet the boot, ultrasound specific functionality can be achieved at the same time, it does not require specially designed driver,the interface is simple and low cost.