【摘要】 USB(Universal Serial Bus)通用串行总线,真正实现了计算机外设的即插即用,因而采用U SB接口的设备越来越多。但USB协议复杂,接口固件程序开发困难。为解决这一问题,采用National Sem iconductor公司生产的严格遵循USB 1.1协议的接口控制芯片USBN 9604,设计固件程序调试系统,文中介绍了USBN 9604芯片的功能,给出了系统硬件电路原理图,详细介绍了固件调试过程中添加式的编程思想。重点说明了中断子程序设计时应注意的问题。试验结果准确,固件程序调试成功。大大缩短了USB接口开发的周期。印证了该系统调试固件程序方便可行。更多还原

【Abstract】 USB(Universal Serial Bus),an external Bus standard supports PlugandPlay installation and hot plugging.The products used USB are more and more.But the protocol of USB is complicated,and it is difficult to empolder the interface′s firmware program.In order to solve this problem,design of debugging firmware program system based on USBN9604.It introduces the function of USBN9604,provides the hardware electrocircuit,and explains how to put the subprogram to the firmware program in this text.It is emphases to introduce how to design the interrupt subprogram and should pay attention to it.The experimentation result is exact,and debugging firmware program is successful.Empolder cycle of USB interface becomes shorter and shorter.It is facility to debug firmware program.更多还原