Howdy, > ummm....what's an SFD?
>> Start of Frame Delimiter. It's a part of MAC header. Yup. At the physical layer a 802.15.4 frame starts with a synchronization header that includes a preamble sequence and then the SFD. Something like four bytes of 0x00 (the preamble sequence) and then an 0xA7 (the SFD). The CC2420 has a lot of support for 802.15.4 framing, so I'm guessing (but not completely sure!) that TinyOS exploits this. Perhaps one of the TEPs go into more detail on this? Regardless, look at section 16 of the CC2420 data sheet for some more gory details of the SFD and its relation to the CC2420. Then you can checkout: CC2420Receive.nc CC2420ReceiveP.nc CC2420TransmitC.nc for how the SFD is being used in the TinyOS 2.x CC2420 driver. Hope that helps! -Roy _______________________________________________ Tinyos-help mailing list [email protected] https://www.millennium.berkeley.edu/cgi-bin/mailman/listinfo/tinyos-help
