usb asp code explanation

[srihari]

hello,
i have downloaded usbasp code for avr programming,i able to understand the whole code but unable to know how the data is read from usb i.e., the two pins connected to controller ,when the data is read is read from that ,i am unable to find the loop for tha in the code

[christian]

This code is in usbdrv/usbdrvasm12.inc or the respective module for your clock rate.