Hello,i'm Diego from Milan ,Italy i did at home a kind of "educational board" with a 9S12 microcontroller and aPDIUSBD12 USB interface i'm trying to implement the protocol to make my USB device enumerated Using this site http://www.beyondlogic.org/usbnutshell/usb7.htm#Enumeration as a reference,of course my firmware will be a little different being my device based on parallel data instead of I2C and having a completely different uController i read the steps in the USB Enumeration process.Focus on steps 3 and 4: 3)The MS Windows host asks for the first 64 bytes of the Device Descriptor. 4)After receiving the first 8 bytes of the Device Descriptor, it immediately issues another bus reset. something is not clear,my micro is going to transfer on the EP0 buffer 64 bytes,and this should be a continous operation , what happens when the USB device encounters a bus reset?it doesn't look like it is signalled to the uController so will the other 56 bytes transferred and wasted?or should I implement an interrupt routine able to stop the not needed transfer? thank you all.
USB protocol and uC ,Help needed
Started by ●September 21, 2007