Texas Instruments SimpleLink CC2620 Technical Reference Manual page 1487

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23.3.2.7.3 Pointer Entry
A pointer entry is an entry where the data are not contained in the entry itself, but the entry holds a pointer
to the buffer. Such an entry is indicated by setting config.type to 2. The pointer replaces the data field, as
shown in Table 23-11.
Byte Index Field Name
8–11 pData
The data is read from or stored in the buffer given by pData. The size of this buffer is given by length, just
as for the size of the data field in a general data entry.
23.3.2.7.4 RX Multielement Entry
For an RX entry, a special variant of the structure in
entry elements can be contained in the same entry. Each entry element typically corresponds to one
packet received over the air, but may contain additional fields. This type is selected by setting config.type
to 1; if config.type is 0 or 2, the radio CPU writes only one entry element into each data entry. In the
multielement entry, the data field is composed as shown in
entire entry structure).
Byte Index Field Name
8–9 numElements
10–11 nextIndex
12–(7+n) RXData
An RX entry that is in the ACTIVE or BUSY state may be read by the system CPU, but cannot be freed or
written to, except for data already committed by the radio CPU (in other words, finished). The system CPU
may read and modify the data in the RXData buffer up to nextIndex-1, while these bytes are not modified
by the radio CPU.
When the radio CPU changes the status of the entry from Pending to Busy, it initializes numElements and
nextIndex to 0.
Each entry element may start with a length indicator as specified by config.lenSz. If this value is 2 so that
a 16-bit length word is used, the length word may not be halfword aligned, and must be read byte by byte.
Two (or more) RX queue entries may be set up in a ring buffer fashion. If so, pCurrEntry of the queue
must be initialized to one of the RX queue entries when setting up the radio operation command, and
pLastEntry must be NULL. pNextEntry of each RX queue entry must be set up to point to the other entry.
Whenever a packet is received, an RX interrupt is raised to the system CPU. The system CPU may then
read the corresponding entry element. If the status of the RX queue entry from which the system CPU is
reading has changed to Finished, the radio CPU writes its next entry element to the other entry. After
processing the received data in the first entry, the system CPU must reset the status field of that entry to
Pending. If this is not done before the radio CPU finishes with the other entry, the radio operation
assumes it is out of buffer space.
SWCU117C – February 2015 – Revised September 2015
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Table 23-11. Pointer Field in Pointer Entry Structure
Bits
Table 23-12. Fields in RX Multielement Structure
Bits
Copyright © 2015, Texas Instruments Incorporated
Bit Field Name Type
W
Table 23-10 may be used. With this type, several
Table 23-12 (the indexes are relative to the
Bit Field
Type
Name
R
R
R
RF Core HAL
Description
Pointer to data buffer of size length
bytes
Description
Number of entry elements
committed in the entry
Index to the byte after the last byte
of the last entry element committed
by the radio CPU
Data received. Exact format
depends on operation being run.
Each entry element may start with
a length byte or word.
Radio
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