關鍵詞：Rapidio, 嵌入式, linux
概述
SRIO是面向嵌入式系統開發提出的高可靠、高性能、基於包交換的新一代高速互聯技術，已於2004年被國際標準化組織(ISO)和國際電工協會(IEC)批准爲ISO/IECDIS18372標準。SRIO則是面向串行背板、DSP和相關串行數據平面連接應用的串行RapidIO接口。
RapidIO互聯主要通過RapidIO交換芯片實現，研製RapidIO交換芯片的廠商主要有Tundra公司、IDT公司和Redswitch公司等。Redswitch公司的產品及應用都較少，Tundra公司後併入IDT公司。IDT公司提供了多種高性能，低功耗的RapidIO交換芯片.
SRIO模式
DirectIO（讀寫內存）
Read/write operations directed to specificmemory address
Functional units:
– LSU (Load/Store Unit)
– MAU (Memory Access Unit)
Message Passing（消息交換）
Mailbox and Letter designators
Functional units:
– TXU (Message Transmit Unit)
– RXU (Message Receive Unit)
24 Interrupt outputs / 8Interrupt outputs
1 MB LSU transaction size with queuingcapability/ single 4 KB LSU transaction size
A Tx/Rx pair on a single device is called a“link”or “lane”
Linux Rapidio
srio 驅動抽象對象 Master Port, Device,Switch, Network
Each of these componentsis mapped into a subsystem structure. The RapidIO subsystem uses thesestructures as the root handle for manipulating the hardware componentsabstracted by the structures.
Riotools quick setup:
1. Load the RIO driver moduleusing modprobe rio.
2. Verify the module hassuccessfully loaded using the lsmodcommand. The output shouldcontain references to the rio module.
3. Ensure all your RIO devices areattached and powered on.
4. Upload the host card firmwareto the driver and boot the attached devices (ignore anywarning or errormessages): rioboot –f
5. Create a configuration file(/etc/rio/rio.cf) based on what is attached to your system: rioboot -w > /etc/rio/rio.cf.new
6. Modify the new configurationfile (/etc/rio/rio.cf.new) to give your RTA's names and assign ports to them.Then rename the file as /etc/rio/rio.cf.
7. Upload the changes to the driver:rioboot –u
8. Create device nodes for theattached RTA's: riomkdev
9. Your system now has a number ofdevice nodes (/dev/ttySR*) relating to the ports on the attached RTA's.
單板系統
CommAgilityAMC-2C87W3雙DSP+FPGA板卡
1)雙DSP，採用TI TCI6487多核DSP，1.2GHz，每個DSP有兩路1×RapidIO接口
2) XilinxVirtex-5 LX110T-2 FPGA，一路4×RapidIO接口
3)通過AMC接口擴展3路4×RapidIO接口
Tsi578芯片是Tundra公司推出的RapidIO交換產品，後併入IDT公司，該芯片基於RapidIO 1.3規範，共有16路串行通道，可以靈活配置爲8×4或16×1的端口工作方式，(同上）2.5或3.125Gbaud的傳輸速率。
參考
http://www.rapidio.org/whitepapers-presentations/
http://baike.baidu.com/subview/6192982/6281112.htm
http://linux-c6x.org/wiki/index.php/Serial_RapidIO