引用 6 楼 huntercao 的回复: 如果拔出usb，只能收到IRP_MN_SURPRISE_REMOVAL 中断，没有IRP_MN_REMOVE_DEVICE。在我关闭上层烧代码的应用时，才会收到IRP_MN_REMOVE_DEVICE中断。 ->关闭上层烧代码的应用之后，系统才会真正Remove设备，才会发IRP_MN_REMOVE_DEVICE。你想啊，关闭程序前，你的应用程序还占用着设备的Handle呢。

引用 23 楼 gooogleman 的回复: 引用 9 楼 oneonce 的回复:主要是不知道那家公司，我是见过别人拿了一块板子他说是那样实现的。 呵呵，这个板子我拿过来测试过。呵呵 在这里http://blog.eeworld.net/gooogleman/archive/2009/10/27/4730053.aspx

引用 1 楼 oneonce 的回复: 引用楼主 halfboy 的回复: 如题，我的cpu是s3c2440，芯片连接的片选是nGCS4，这样地址就应该是0x20000000。但是驱动下面偏移地址使用的是0x20000300，这个是怎么得到的，恳请大家知道的给以解惑！ 貌似改成0x20000000也是可以，一直没注意多了个0x300的问题，我的也有。

引用 5 楼 tcdl85 的回复: 引用 4 楼 guopeixin 的回复: 1. 以前有人讨论过这些问题，你看看和你有没有类似的地方 http://topic.eeworld.net/u/20090916/10/6009396f-54a7-427e-90c0-f2723e58cf4f.html?seed=415955654&r=59851966#r_59851966 2。to：u盘是FAT32的4GB　组件都加上了　感觉要开机等一段时间才能识别到U盘的 u盘比较大而且上面文件比较多的时候，识别时间是需要很久 你可以格式化后重新测试这个时间 3。to：特别不稳定。。。有的时候可以识别。。。有的时候识别不了 这个地方可能就是驱动或者hw的问题了 终于在万能的google上搜索到了答案,以下是EP93xx的bugfix 实验证明对于s3c24xx也是有用的 The file describes the cause and the fix of Windows CE 5.0's USB device detection problem during power-up.? 1. USB Device Detection Problem during Powering-Up ? - Connect USB devices to EDB93xx's USB ports when the board is ? ? powered-off. ? - Power on EDB93xx. ? - Wait until CE 5.0 is fully loaded. ? - One or several USB devices are not detected by CE 5.0. 2. The Cause ? In USB's Open Host Controller Interface (OHCI) Specification, in ? Register HcRhDescriptorA (EP93xx address 0x80020048), Bits 24-31 ? are PowerOnToPowerGoodTime. This POTPGT byte specifies the duration ? Host Controller Driver has to wait before accessing a powered-on port ? of the Root Hub.? It is implementation-specific.? The unit of time ? is 2 msec. The duration is calculated as POTPGT x 2msec. ? EP93xx's default value of Register HcRhDescriptorA is 0x02001203. ? The value of the POTPGT byte is 0x02. 2*2msec=4msec. It needs 4 msec ? delay after the Host Controller has supplied power to the Root Hub. ? ? The start-up sequence for EDB93xx's USB host controller should be ? 1. Host Controller supplies power to the Root Hub. ? 2. Delay 4 msec. ? 3. Set Host Controller to Operational state. Access USB ports. Start ? ? ? to send SOF tokens...etc. ? CE 5.0's USB driver doesn't implement the code to read the HcRhDescriptorA ? register and deploy the required delay.? ? ? 3. The Fix: ? ? Add the 4-msec delay to CE's USB host driver then rebuild the platform. ? Modify the filebr>? WINCE500\PUBLIC\COMMON\OAK\DRIVERS\USB\HCD\OHCD2\chw.cpp ? Please look at the code "//QQQQQ" below. BOOL CHW::Initialize(void) { .................. ? ? InterruptDisable( m_dwSysIntr ); // Just to make sure this is really ours. ? ? // Initialize Interrupt. When interrupt id # m_sysIntr is triggered, ? ? // m_hUsbInterruptEvent will be signaled. Last 2 params must be NULL ? ? if ( !InterruptInitialize( m_dwSysIntr, m_hUsbInterruptEvent, NULL, NULL) ) { ? ? ? ? DEBUGMSG(ZONE_ERROR, (TEXT("-CHW::Initialize. Error on InterruptInitializern"))); ? ? ? ? return FALSE; ? ? } ? ? // Apply power to all root hub ports, just like OHCI. ? ? m_portBase->HcRhDescriptorA.NPS = 1; ? ? m_portBase->HcRhStatus.reg= HcRegisters::HcRhStatus:PSC; //QQQQQQQ Add 4msec delay that is required by Host Controller. Sleep(4);? ? ? ? ? // Start up our IST - the parameter passed to the thread ? ? // is unused for now ? ? DEBUGCHK( m_hUsbInterruptThread == NULL && ? ? ? ? ? ? ? m_fUsbInterruptThreadClosing == FALSE ); ? ? m_hUsbInterruptThread = CreateThread( 0, 0, UsbInterruptThreadStub, this, 0, NULL ); ? ? if ( m_hUsbInterruptThread == NULL ) { ? ? ? ? DEBUGMSG(ZONE_ERROR, (TEXT("-CHW::Initialize. Error creating ISTn"))); ? ? ? ? return FALSE; ? ? } ? ? CeSetThreadPriority( m_hUsbInterruptThread, g_IstThreadPriority ); ...................... } 应该就是这个了

引用 6 楼 lyx_wq 的回复: 看外部晶振 然后看软件内部的分频比不就可以算出来了？？