Posted on May 17, 2011 at 12:07I am starting new project with USB interafce.
Fisrst step I have check all with ST sample and all work OK
Second step I have write mi own code and after first test I have some questions:
I start my application next I connect USB cable to PC.
I also store the UISTA value for the first interrupt only:
unsigned char flag = 0x00 ;
unsigned char tmp = 0xFF ;
USBIsr()
{
if (flag==0) {tmp = UISTA ; flag =1 }
....
}
Every 500ms I copy to SBUF the tmp value and I send to PC via serial port. (serial connection tested)
The read value is 0x00 !! Why the vector interrupt start if UISTA = 0 ?
thanks for help
