CC2520_11 Datasheet, PDF (79/133 Pages) Texas Instruments – 2.4 GHZ IEEE 802.15.4/ZIGBEE RF TRANSCEIVER

CC2520 DATASHEET
2.4 GHZ IEEE 802.15.4/ZIGBEE® RF TRANSCEIVER
SWRS068 – DECEMBER 2007
Short Source Address (mode 2)
Extended Source Address (mode 3)
The received source PAN ID is called srcPanid. The received extended address is called srcExt.
The received short address is called srcShort.
SRCRESMASK = 0x000000;
SRCRESINDEX = 0x3F;
for (n = 0; n < 24; n++) {
bitVector = 0x000001 << n;
if (SRCSHORTEN & bitVector) {
if ((panid[n] == srcPanid) &&
(short[n] == srcShort)) {
SRCRESMASK |= bitVector;
if (SRCRESINDEX == 0x3F) {
SRCRESINDEX = n;
}
}
}
}
SRCRESMASK = 0x000000;
SRCRESINDEX = 0x3F;
for (n = 0; n < 12; n++) {
bitVector = 0x000003 << (2*n);
if (SRCEXTEN & bitVector) {
if (ext[n] == srxExt) {
SRCRESMASK |= bitVector;
if (SRCRESINDEX == 0x3F) {
SRCRESINDEX = n | 0x20;
}
}
}
}
Figure 23 - Matching algorithm for short and extended addresses
SRCRESMASK and SRCRESINDEX are written to CC2520 memory as soon as the result is available.
SRCRESINDEX is also appended to received frames if the FRMCTRL0.AUTOCRC and
FRMCTRL0.APPEND_DATA_MODE bits have been set. The value then replaces the 7-bit LQI value of the
16-bit status word.
Exceptions
When source address matching is enabled and the matching algorithm completes, a SRC_MATCH_DONE
exception will be generated, regardless of the result. If a match is found, a SRC_MATCH_FOUND exception
will also be generated, immediately before SRC_MATCH_DONE.
Figure 24 illustrates the timing of these exceptions:
Figure 24 - Exceptions generated by source address matching
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