when you carelessly set the endpoint size to be 512. but you set the AUTOINLEN 1024. then 68013 would invariably transfer a zero-length packet after each transfer. casually i come across the phenomenum: even i didn't allow zerolen in EPxFIFOCFG, 68013 stubbornly commit a zerolength packet . and this made my application softwaare frequently break down my computer. my computer experience blue screen more than ten time. but finally i find the cause. so share it to each developer
