Commands To Fifo Via Rfst Register; Access To Fifo Registers - Texas Instruments CC253x User Manual

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The supported FIFO commands are listed in
not match any of the listed commands is ignored.
Number
0x81
0x82
0x83
0x84
0x85
0x91
0x92
0x93
0x94
0x95
0xF1
0xF2
0xF3
0xF4
0xF5
25.3.1.3 FIFO Pointer Operations
The FIFO pointers can be accessed directly through registers RFFRXFWP, RFFRXFRP, RFFRXFSWP,
RFFRXFSRP, RFFTXFWP, RFFTXFRP, RFFTXFSWP, and RFFTXFSRP.
Because the placement of the pointers may be the same for an empty and a full FIFO, there are internal
states distinguishing between these situations. This means that although any value can be written to the
pointer registers, certain rules must be observed for the FIFO to function reliably after the pointer write.
Any writes to a pointer must be considered to move that pointer up. Hence, writing N to a pointer already
holding N is considered equivalent to moving that pointer up 128 places, writing N-1 is equivalent to
moving the pointer up 127 places, and so on.
The pointers must maintain a specific ordering: (Going from lowest position to highest) SRP, RP, SWP,
WP.
A lower pointer may be moved up to but not past a higher pointer, whereas the highest pointer (WP) may
be moved down to, but not past the lower.
25.3.1.4 Cooperation With LLE
The LLE performs FIFO operations as part of its operation. In order to avoid conflicts between the LLE
and the MCU, access to FIFO registers should be done according to
always be made, except for the data-read registers, which causes the read pointers to be modified. If the
MCU reads a register, one must take into account that the value may change at any time due to accesses
from the LLE. The reset FIFO commands should only be run by the MCU between LLE tasks. They are
marked with an asterisk in
Register
RFD
SWRU191F – April 2009 – Revised April 2014
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Table
Table 25-2. Commands to FIFO via RFST Register
Command Name
CMD_RXFIFO_RESET
CMD_RXFIFO_DEALLOC
CMD_RXFIFO_RETRY
CMD_RXFIFO_DISCARD
CMD_RXFIFO_COMMIT
CMD_TXFIFO_RESET
CMD_TXFIFO_DEALLOC
CMD_TXFIFO_RETRY
CMD_TXFIFO_DISCARD
CMD_TXFIFO_COMMIT
CMD_FIFO_RESET
CMD_FIFO_DEALLOC
CMD_FIFO_RETRY
CMD_FIFO_DISCARD
CMD_FIFO_COMMIT
Table 25-3.
Table 25-3. Access to FIFO Registers
Read Access
MCU
Copyright © 2009–2014, Texas Instruments Incorporated
25-2. A command in the range of 0x80–0xFF that does
Description
Reset (empty) RX FIFO. Set
Deallocate RX FIFO. This sets
Retry RX FIFO. This sets
Discard RX FIFO. This sets
Commit RX FIFO. This sets
Reset (empty) TX FIFO. Set
Deallocate TX FIFO. This sets
Retry TX FIFO. This sets
Discard TX FIFO. This sets
Commit TX FIFO. This sets
Reset both FIFOs
Deallocate both FIFOs
Retry both FIFOs
Discard both FIFOs
Commit both FIFOs
Table 25-3. Read accesses can
CC2541 Proprietary Mode Radio
RF Core Data Memory
RFRXF
* := 0
RFRXFSRP RFRXFRP
:=
RFRXFRP RFRXFSRP
:=
RFRXFWP RFRXFSWP
:=
RFRXFSWP RFRXFWP
:=
RFRXF
* := 0
RFTXFSRP := RFTXFRP
RFTXFRP := RFTXFSRP
RFTXFWP RFTXFSWP
:=
RFTXFSWP RFTXFWP
:=
Write Access
MCU
.
.
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