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Is it possible to detect  NAKed IN transactions?

Question asked by David Galbarra on Jun 23, 2011
Latest reply on Jun 30, 2011 by David Galbarra

Hi all

 

I am using AN3564 USB Stack with a HCS08JM32  microcontroller, and I have successfully configured an Interrupt endpoint on EP1. The Host is supposed to initiate an IN transaction every 10 ms, and when the device has some data to send, It can be detected at USB_Transaction_Handler, at this line:

 

void USB_Transaction_Handler(void)

unsigned char stat = STAT;

 

...

if( (stat &0xF8) == 0x18){

//this is an IN transaction at Endpoint 1

...

}

 

But now I would like to detect all the NAKed IN Transactions, because I pretend the device to notice if USB Host is disconnected by some reason. I know I could detect that with the SOF packets, but I'm trying to detect an strange condition where the Host stops sending the IN Transaction but remains connected and sending the Start Of Frame packets.

 

Does anybody know If it is possible to detect the NAKed IN transactions?

 

Thanks for your help!

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