| It gives something like that in low speed 
mode after bit stuffing and NRZI encoding : (IDLE)        
SYNC            
NOTPID-PID        DEVICE 
ADDRESS        ENDPOINT ADDRESS    
    CRC5        
SE0        JSTATE    
    (IDLE)           
    01010100           0111 
0010                 1010101                            0101                         
01011 Since every obvious byte is right the problem must 
lie in the CRC5. I'm not sure I'm right on this particular one. You can use the usbf_crc5.v file in the USB 2.0 
function core to generate your CRC5 look at usbf_pa.v or usbf_pd.v to know the 
exact input order 
 |