Texas Instruments SimpleLink CC2620 Technical Reference Manual page 1533

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If frameFiltOpt.frameFiltStop is 1 and the frame filtering gives the conclusion that the frame is to be
rejected, reception stops and the radio returns to sync search. Otherwise, the frame is received to the end.
The radio CPU checks the header to see if an acknowledgment is to be transmitted. This gives a
preliminary result; the actual transmission of the ACK depends on the status at the end of the frame. The
condition for transmitting an acknowledgment frame is given in
23.5.4.1.1.2 Source Matching
Source matching is performed on frames accepted by the frame filtering with a source address present. If
the source address was an extended address, the received address is compared against the entries in the
list pExtEntryList. If the source address was a short address, the received address and source pan ID are
compared against the entries in the list pShortEntryList.
The number of entries that the lists can hold is given by numExtEntries and numShortEntries. If either of
these values are 0, no source matching is performed on addresses of the corresponding type, and the
corresponding pointer is NULL. The lists start with source mapping enable bits, srcMatchEn, and continue
with pending enable bits, srcPendEn, followed by the list entries, see
enable bits consist of the number of 32-bit words needed to hold an enable bit for each entry in the list.
For each entry where the corresponding srcMatchEn bit is 1, the entry is compared against the received
source address for extended addresses, or against the received source address and PAN ID for short
addresses. If a match is found, the index is stored, and reported back in the message footer if configured
(see Section 23.6.3.1). If no match is found, the index reported back is 0xFF.
The source matching procedure may also be used for finding the pending data bit to be transmitted in an
auto-acknowledgment frame (see
was found, the pending data bit is set to the value of the bit in srcPendEn corresponding to the index of
the match. If no match was found or if frameFiltOpt.autoPendEn is 0, the pending data bit is set equal to
frameFiltOpt.defaultPend. If frameFiltOpt.bPendDataReqOnly is 1, the radio CPU investigates the frame to
determine if it is a MAC command frame with the command frame identifier set to a Data Request. If not,
the pending data bit of an auto ACK is set equal to 0, regardless of the source matching result and the
value of frameFiltOpt.defaultPend.
23.5.4.1.2 Frame Reception
After the frame filtering is done, the rest of the packet is received and stored in the receive queue. The
last two bytes of the PHY packet is the MAC footer, or FCS, which is a checked CRC. The CRC is only
stored in the queue if rxConfig.bIncludeCrc is 1.
The status of the received frame depends on the frame filtering result and the CRC check result. Two
status bits bCrcErr and bIgnore must be maintained. If configured, these bits are present in the Status
byte of the RX queue entry. The bCrcErr bit is 1 if the frame had a CRC error, and 0 otherwise. The
bIgnore bit is 1 if frame filtering is enabled and the frame was rejected by frame filtering, and 0 otherwise.
NOTE: If frameFiltOpt.frameFiltStop is 1, frames with bIgnore equal to 1 are never observed, as the
reception is stopped and the received bytes are not stored in the queue. If
rxConfig.bAutoFlushCrc is 1, packets with bCrcErr equal to 1 are removed from the queue
after reception, and if rxConfig.bAutoFlushIgn is 1, packets with bIgnore equal to 1 are
removed from the queue after reception.
After a packet has been received, an interrupt is raised and one of the counters in pOutput is incremented.
The conditions are as given in
Table 23-80. Conditions for Incrementing Counters and Raising Interrupts for RX Operation
Condition
Frame received with CRC OK and frame filtering disabled
Frame received with CRC error
Frame received that did not fit in the RX queue
Beacon frame received with CRC OK and bIgnore = 0
SWCU117C – February 2015 – Revised September 2015
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Section 23.5.4.1.3). If frameFiltOpt.autoPendEn is 1 and a source match
Table 23-80.
Counter Incremented
nRXData
nRXNok
nRXBufFull
nRXBeacon
Copyright © 2015, Texas Instruments Incorporated
Section 23.5.4.1.3.
Table 23-73 and Table
Interrupt Generated
RX_OK
RX_NOK
RX_BUF_FULL
RX_OK
IEEE 802.15.4
23-74. The
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Radio