CP3BT23 Datasheet, PDF (8/260 Pages) Texas Instruments – CP3BT23 Reprogrammable Connectivity Processor with Bluetooth and Dual CAN Interfaces

3.21 DMA CONTROLLER
3.22 SERIAL DEBUG INTERFACE
The Direct Memory Access Controller (DMAC) can speed The Serial Debug Interface module (SDI module) provides
up data transfer between memory and I/O devices or be- a JTAG-based serial link to an external debugger, for exam-
tween two memories, relative to data transfers performed di- ple running on a PC. In addition, the SDI module integrates
rectly by the CPU. A method called cycle-stealing allows the an on-chip debug module, which allows the user to set up to
CPU and the DMAC to share the CPU bus efficiently. The eight hardware breakpoints on instruction execution and
DMAC implements four independent DMA channels. DMA data transfer. The SDI module can act as a CPU bus master
requests from a primary and a secondary source are recog- to access all memory mapped resources, such as RAM and
nized for each DMA channel, as well as a software DMA re- peripherals. Therefore it also allows for fast program code
quest issued directly by the CPU. Table 1 shows the DMA download into the on-chip Flash program memory using the
channel assignment on the CP3BT23 architecture. The fol- JTAG interface.
lowing on-chip modules can assert a DMA request to the _{Note: The SDI module may assert Freeze mode to gather}
DMAC:
information, which may cause periodic fluctuations in re-
• CR16C (Software DMA request)
sponse (bus availability, interrupt latency, etc.). Anomalous
• USART
• Advanced Audio Interface
• CVSD/PCM Converter
Table 1 shows how the four DMA channels are assigned
to the modules listed above.
Table 1 DMA Channel Assignment
te ^Channel
Primary/
Secondary
Primary
0
Secondary
le ^Primary
1
Secondary
Primary
2
o ^Secondary
Peripheral
Reserved
UART0
UART0
Unused
AAI
CVSD/PCM
Transaction
Read/Write
Read
Write
N/A
Read
Read
behavior often may be traced to SDI activity.
3.23 DEVELOPMENT SUPPORT
In addition to providing the features needed for the next gen-
eration of embedded Bluetooth products, the CP3BT23 de-
vices are backed up by the software resources designers
need for rapid product development, including an operating
system, Bluetooth protocol stack implementation, peripher-
al drivers, reference designs, and an integrated develop-
ment environment. Combined with National’s LMX5251
Bluetooth radio transceiver, the CP3BT23 devices provide a
total Bluetooth system solution.
National Semiconductor offers a complete and industry-
proven application development environment for CP3BT23
applications, including the IAR Embedded Workbench,
iSYSTEM winIDEA and iC3000 Active Emulator, Bluetooth
Development Board, Bluetooth Protocol Stack, and Applica-
tion Software. See your National Semiconductor sales rep-
resentative for current information on availability and
features of emulation equipment and evaluation boards.
Primary
AAI
3
Secondary CVSD/PCM
Write
Write
s _{The interface can handle data words of either 8- or 16-bit}
length and data frames can consist of up to four slots.
b ^{In the normal mode of operation, the interface only transfers}
one word at a periodic rate. In the network mode, the inter-
face transfers multiple words at a periodic rate. The periodic
rate is also called a data frame and each word within one
frame is called a slot. The beginning of each new data frame
O ^{is marked by the frame sync signal.}
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