USB Device OVERVIEW

                                   USB Device OVERVIEW                    

  这是本人分析IAR USB CDC的认识

1 Software Initialization:

 

Step	Function
1	Fill Description
2	Fill Device Interruption Handler
3	Fill Interface Interruption Handler
4	Fill EP In Interruption Handler
5	Fill EP Out Interruption Handler
6	Create Rx FIFO
7	Create Tx FIFO
8	Fill Hardware Register
9	Connect the USB device to BUS

 

2 Standard Requests

 

3 EP data in

      

Step	Function
1	EP In Interruption Read data
2	EP In Interruption Write Rx FIFO
3	Application read data from Rx FIFO

      

4 EP data out

      

Step	Function
1	Application write data to TX FIFO
2	EP Out Interruption Read TX FIFO
3