The ACK should be generated for the packet you're currently reading out of the RXFIFO. The ACK will only be issued if the packet you're currently reading out has a valid CRC.
-David -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Liusand Sent: Thursday, March 13, 2008 8:58 AM To: tinyos-help@millennium.berkeley.edu Subject: [Tinyos-help] Which packet in RXFIFO is SACK acking? Hi, I have a question on the SACK command strobe for CC2420. As we know, the RXFIFO can hold several packets as long as the total length is no more than 128. Hence, when the first packet is read out and then a SACK command is issued, which packet in the RXFIFO queue is the ack for? I checked CC2420ReceiveP.nc in T2, and it seems the ack is for the packet just read out. But some discussions on devel mailing-list said opposite. Can anyone help me undertand this? Thanks, Sha _______________________________________________ Tinyos-help mailing list Tinyos-help@millennium.berkeley.edu https://www.millennium.berkeley.edu/cgi-bin/mailman/listinfo/tinyos-help _______________________________________________ Tinyos-help mailing list Tinyos-help@millennium.berkeley.edu https://www.millennium.berkeley.edu/cgi-bin/mailman/listinfo/tinyos-help