2005-05-31 02:27 AM
2011-05-17 03:07 AM
I 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