[Tinyos-help] AM Group Address Verfication in CC2420

[Greg Hackmann]

Dodda Venkatappa Manjunath wrote:
>     As the TOS_GROUP_ID is written into CC2420's RAM (m_pan in writeId() 
> of CC2420ControlP ), I am wondering whether a message that does not 
> belong to the
> node's GROUP is dropped in a software component or CC2420 chip. I was 
> not able to find the corresponding code in any of the software 
> components consituting CC2420 based AM stack.

The CC2420 chip has a feature called hardware address recognition, which 
will automatically drop any packets addressed to another node (including 
nodes in other AM groups).  TinyOS's CC2420 stack enables this feature 
by default.  It can be disabled at compile-time by #defining 
CC2420_NO_ADDRESS_RECOGNITION, or at runtime by calling the 
setAddressRecognition() command on CC2420ControlC's CC2420Config interface.

Greg Hackmann