USB SOF doubt

xxopiumxx · Joined: 01 Jul 2011 Posts: 20

greetings,

I have reading upside down the entire usb.c pic18_usb.c etc etc etc libraries, but I cannot find any code relating to the SOF token. As I know, it must be sent every 1ms (in full speed) in order to prevent a suspended mode entering.
Of course it is being sent, otherwise my program wouldn't work at all, but as curious as I am, I wanted to know if you can give me a tip about this.

Thanks for advance.

temtronic · Posted: Mon May 28, 2012 1:19 pm

If you really,really NEED to know about it, I suggest Jan's bible on USB. Somewhere in the 500-600 pages of dull,dreary reading you'll come across it....
As for the CCS drivers,again, just read the code, line by line, it's there if it needs to be...

Frankly I've got better things to do than dive into the workings of the Useless Serial Bus.

FvM · Joined: 27 Aug 2008 Posts: 2337 Location: Germany

You find the basic information even in the USB chapter of the PIC18 datasheet. SOF is send from host to device. The device don't answer the SOF, only succeeding explicite commands, if any.

xxopiumxx · Joined: 01 Jul 2011 Posts: 20

thanks, pals