bare metal project for usb mouse

Attachment: ADC.c (19.96 KB)

I'm doing a project for a computer mouse based on the usb driver, but stuck
at the very beginning.

When I read the value of register rEPO_CSR, it gives me the value 0x0,
although in theory it should not. What am I doing wrong? I enclose the code
in the attached file. Also here is the conclusion that I see on the screen
of my Mini2440:

13-Test RT clock                                                    
14-Test USB Mouse                                             
End of ReconfigUsbd()                                                    
I in end of ConfigUsbd()                                                  
I in Test_Adc. Must start Ep0Handler().                                   

I am working in NOR(bare) mode of Mini2440.