Texas Instruments SimpleLink CC2620 Technical Reference Manual page 1594

Proprietary Radio
23.7.5.4.1 Standard Receive Command, CMD_PROP_RX
The CMD_PROP_RX receives packets with the format from
Figure 23-9. The parameters are as given in
The modem configures the receiver and starts listening for sync. The sync word to listen for is given in the
syncWord field, in the LSBs if less than 32 bits are used. The word is in the bit order programmed in the
radio.
If sync is found, the radio CPU starts receiving data. If pktConf.bVarLen is 1 and maxPktLen is nonzero, a
length byte is assumed as the next byte. This length byte is compared to maxPktLen, and if it is greater,
reception is stopped and synch search is restarted. Otherwise, this indicates the number of bytes after the
length byte and before the CRC. If pktConf.bVarLen is 0, the length is fixed, and the receiver assumes
maxPktLen bytes after the sync word and before the CRC. If maxPktLen is zero, the length is unlimited as
described in the beginning of
If pktConf.bChkAddress is 1, an address byte is checked next. The address byte is checked against the
values of address0 and address1. If only one address is needed, these two fields must be set to the same
value. If address1 is 0xFF, it is also checked against the value 0x00. To check for 0xFF without checking
for 0x00, address0 must be the one set to 0xFF. If the address byte does not match the configured
addresses, the further treatment depends on pktConf.filterOp. If this is 0, reception is stopped and synch
search is restarted. If it is 1, the packet is received as if the address had matched, but it is marked as
ignored.
If the packet is being received, the data is placed in the receive buffer, as in
Buffers. This receive buffer is found from the receive queue pointed to by pQueue. If pQueue is NULL, the
packet is never stored.
If pktConf.bUseCrc is 1, a CRC is received and checked at the end. The number of CRC bits, polynomial,
and initialization are as configured in the radio. The CRC is calculated over the length byte (if present), the
optional address, and the payload. If pktConf.bUseCrc is 0, the treatment is as for CRC OK.
If whitening is enabled, the optional length byte, the payload including the optional address, and the
received CRC are subject to dewhitening. The dewhitening is done before the CRC is evaluated.
If a status byte is appended (RXConf.bAppendStatus is 1) to the packet, it is formatted as follows (see
Table 23-107). If pktConf.addressMode is nonzero, the addressInd field is 0 if the address matched
address0, 1 if it matched address1, 2 if it matched 0x00 and this address was enabled, and 3 if it matched
0xFF and this address was enabled. Otherwise, addressInd is 0. The syncWordId field is always 0 for
CMD_PROP_RX. The result field is written according to
23.7.5.4.2 Advanced Receive Command, CMD_PROP_RX_ADV
The CMD_PROP_RX_ADV is used for receiving packets with the format from
case, the user can set up packets as in
The modem configures the receiver and starts listening for sync. The sync word to listen for is given in the
syncWord0 field, in the LSBs if less than 32 bits are used. The word is in the bit order programmed in the
radio. If syncWord1 is nonzero, the receiver also listens for the sync word given in the syncWord1 field
(formatted in the same way) if supported in the MCE.
If sync is found, the radio CPU starts receiving data. The packet may contain a header, which can consist
of any number of bits up to 32, given by hdrConf.numHdrBits. If the number of bits in the header does not
divide by 8, it is considered to consist of a sufficient number of bytes to contain all the stored bits, as in
Section 23.5.3.1, Receive Buffers. This header may contain a length field or an address.
The received packet may have fixed or variable length. If hdrConf.numLenBits is 0 and maxPktLen is
nonzero, the packet has a fixed length, consisting of maxPktLen bytes after the header and before the
CRC. If hdrConf.numLenBits is greater than 0, a field of hdrConf.numLenBits, read from bit number
hdrConf.lenPos from the LSB of the header, is taken as a length field. The signed number lenOffset is
added to the received length to give the number of bytes after the header and before the CRC. If this
number is less than or equal to maxPktLen, the packet is received. If maxPktLen is zero, the length is
unlimited as described in the beginning of
CMD_PROP_RX_ADV differs from the one for CMD_PROP_TX_ADV , see
header is included in the packet length.
1594
Radio
Table 23-139.
Section 23.7.5.4.
Figure 23-9. The parameters are as given in
Section 23.7.5.4. The definition of packet length for
Copyright © 2015, Texas Instruments Incorporated
Section
Table 23-151.
Figure
Section 23.7.5.4.2
SWCU117C – February 2015 – Revised September 2015
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23.5.3.1, Receive
23-10. As a special
Table 23-140.
where the