C6748 USB_dev_msc的问题请教

只看该作者 · 2016-3-9 17:48

大神们：
下面是USB_dev_msc主函数的主循环，我真的没看出来他是怎么调用读写函数进行USB读写的，还是说他就是等着用户自己在“// If there is no activity then return to the idle state.”处填写读写动作呢？？
while(1)
{
      switch(g_eMSCState)
      {
         case MSC_DEV_READ:
         {
            //
            // Update the screen if necessary.
            //
            if(g_ulFlags & FLAG_UPDATE_STATUS)
            {
                  UpdateStatus("Reading", 0);
                  g_ulFlags &= ~FLAG_UPDATE_STATUS;
            }

            //
            // If there is no activity then return to the idle state.
            //
            if(g_ulIdleTimeout == 0)
            {
                  UpdateStatus("Idle    ", 0);
                  g_eMSCState = MSC_DEV_IDLE;
            }

            break;
         }
         case MSC_DEV_WRITE:
         {
            //
            // Update the screen if necessary.
            //
            if(g_ulFlags & FLAG_UPDATE_STATUS)
            {
                  UpdateStatus("Writing ", 0);
                  g_ulFlags &= ~FLAG_UPDATE_STATUS;
            }

            //
            // If there is no activity then return to the idle state.
            //
            if(g_ulIdleTimeout == 0)
            {
                  UpdateStatus("Idle    ", 0);
                  g_eMSCState = MSC_DEV_IDLE;
            }
            break;
         }
         case MSC_DEV_IDLE:
         default:
         {
            break;
         }
      }