Fifos; Mapping Of Radio Memory To Mcu Xdata Memory Space; Fifo Pointers - Texas Instruments CC253x User Manual

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Figure 25-1. Mapping of Radio Memory to MCU XDATA Memory Space

25.3.1 FIFOs

The FIFOs are used for transporting data between the MCU and the radio. The FIFOs have hardware
support for read and write pointer increment with circular buffering, overflow and underflow detection, and
flushing of last entry or the entire FIFO.
The RX and TX FIFOs are fundamentally two similar modules. Each FIFO has four pointers: the write
pointer (WP), the read pointer (RP), the start-of-packet write pointer (SWP), and the start-of-packet read
pointer (SRP). WP and RP give the index in the FIFO where the next byte is to be written and read,
respectively. SWP is used to indicate the start of the current packet being written, and SRP is used to
indicate the start of the current packet being read. The use of the pointers is indicated in
SWRU191F – April 2009 – Revised April 2014
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Last Packet
SWP
n -Packets
RP
First Packet
SRP
Free Space
WP
0
Figure 25-2. FIFO Pointers
Copyright © 2009–2014, Texas Instruments Incorporated
0x61F7
Radio XREG
0x6180
0x617F
Tx FIFO
0x6100
0x60FF
Rx FIFO
0x6080
0x607F
Radio RAM
0x6000
M0219-01
M0220-01
CC2541 Proprietary Mode Radio
RF Core Data Memory
Figure 25-2.
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