[Tinyos-devel] 2.0.2 CC2420

[David Moss]

Yup - there's a good reason for this.  The destination address is checked
automatically by hardware while receiving the packet transmission.  So by
the time the uC gets the signal that a new packet has arrived, the packet
has already gone through the address/pan check.  Therefore, we don't need a
second address check in software before issuing a SACK.

-David


-----Original Message-----
From: David Moss [mailto:dmm at rincon.com] 
Sent: Tuesday, July 03, 2007 9:45 PM
To: 'Chieh-Jan (Mike) Liang'
Cc: 'tinyos-devel at Millennium.Berkeley.EDU'
Subject: RE: [Tinyos-devel] 2.0.2 CC2420

Yup - there's a good reason for this.  The destination address is checked
automatically by hardware while receiving the packet transmission.  So by
the time the uC gets the signal that a new packet has arrived, the packet
has already gone through the address/pan check.  Therefore, we don't need a
second address check in software before issuing a SACK.

-David



-----Original Message-----
From: Chieh-Jan (Mike) Liang [mailto:cliang4 at cs.jhu.edu] 
Sent: Tuesday, July 03, 2007 7:41 PM
To: David Moss
Cc: tinyos-devel at Millennium.Berkeley.EDU
Subject: Re: [Tinyos-devel] 2.0.2 CC2420

Something about SACK in the new CC2420 stack is not clear to me. In the 
old implementation, before SACK is strobed, the mote ID is compared with 
the packet destination address. However, this check is not performed any 
more. Is there any reason behind this?

Thank you

Mike

David Moss wrote:
> Just updated the CC2420 stack in preparation for 2.0.2.  The file 
> architecture has been re-arranged a little bit, making it easier to see 
> how the stack is put together.  As a result, the .platform files that 
> reference the cc2420 were updated. 
> 
>  
> 
> Test results are included. Let me know if you have any issues.
> 
> -David
> 
>  
> 
>  
> 
> Recent Updates (from the readme):
> 
> * New chip SPI bus arbitration working with Receive and Transmit.
> 
>  
> 
> * Applied TUnit automated unit testing to CC2420 development
> 
>   > Caught lots of bugs, especially through regression testing
> 
>   > Source code in tinyos-2.x-contribs/tunit/
> 
>  
> 
> * Applied TEP115 behavior to CC2420 SplitControl in Csma and Lpl
> 
>  
> 
> * Updated ActiveMessageAddressC to provide the ActiveMessageAddress 
> interface
> 
>   > Updated CC2420ConfigP to handle 
> ActiveMessageAddress.addressChanged() and
> 
>     sync automatically upon address change events.
> 
>  
> 
> * Updated CC2420Config interface to enable/disable sw/hw acknowledgements
> 
>  
> 
> * Updated CC2420ConfigP to share register editing through single functions
> 
>  
> 
> * Acknowledge after packet length and FCF check out valid. 
> 
>   > The destination address is confirmed in hardware, so we don't need
> 
>     to download the entire header before acking.
> 
>  
> 
> * Moved the getHeader() and getMetadata() commands to an internal
interface
> 
>   called CC2420PacketBody, provided by CC2420PacketC
> 
>  
> 
> * Separated core functionality into different sub-packages/directories
> 
>   > Updated micaz, telosb, intelmote2 .platform files
> 
>   > Logically organizes code
> 
>  
> 
> * Updated some LPL architecture
> 
>   > Removed continuous modulation because it didn't work 100% and I 
> don't have
> 
>     time to make it work. 
> 
>   > Decreased backoffs and decreased on-time for detects, saving energy.
> 
>  
> 
> * Updated to the new AMPacket interface; made the radio set the outbound
> 
>   packet's destpan after send().
> 
>  
> 
>  
> 
>  
> 
> 
> ------------------------------------------------------------------------
> 
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