Then the paper dicusses the implemention of the modem based on dsp , describes the parts of the modem , design and implement the circuit of the modem ' s echo cancek ring detection - , status supervise and power supply after the detailed research on the dsp ' s performance ? function , memory space and work mode . studies the device driver of the ppsm , develops the modem ' s driver , includes the idma read and write , download page , event handle , send data and receive data 随后,论文论述基于dsp的modem的设计,对modem的总体结构进行了描述,在对系统使用的dsp芯片adsp2187的性能、功用、存储器空间和工作模式作了细致研究后,设计和实现了modem的回声抑制、振铃检测、状态监测和电源等硬件电路,并对ppsm操作系统下外设的驱动程序进行了研究,开发了ppsm下modem的驱动程序,包括idma读写、下载页面、事件处理、发送和接收数据的程序。
Many kinds of technology , such as api hook , winsock spi , are utilized in user mode , but the fatal flaw of these kinds of technology is that they are only confined on the winsock layer , so many trojan horses and viruses can directly call tcp / ip through tdi instead of winsock to send and receive data 在用户模式下可以采用apihook 、 winsockspi等技术。但是这些技术最致命的缺点就是只能在winsock层次上进行,一些木马和病毒程序很容易绕开winsock而直接通过tdi调用tcp ip发送和接收数据,那么使用上述的技术显然就无能为力了。
And then this thesis designs the reliable data transfer service from three aspects : packet format , the creation and free of the connection , the sending and receiving of the data . the result of the designation is the connection - oriented sending su and the connection - oriented receiving su . they work together to ensure the function of reliable data transfer 然后从包格式,建立和撤销连接以及发送和接收数据三个方面进行设计,主要的设计结果是有连接发送服务元和有连接接收服务元,它们配合起来共同完成可靠数据传输的功能,并在最后给出了设计的流程图。