基于AT91RM9200微控制器的以太网接口驱动程序设计

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浅谈AT91RM9200的嵌入式网络摄像机的设计与实现

浅谈AT91RM9200的嵌入式网络摄像机的设计与实现1.引言随着通信技术和网络技术的迅猛进展，通过网络远程实时监控重要场所已倍受人们关注，网络摄像机在此背景下产生，并成为人们关注的焦点。

网络摄像机是一种结合传统摄像机与网络技术所产生的新一代摄像机，它可以将影像通过网络传至地球另一端，且远端的扫瞄者不需用任何专业软件，只要标准的网络扫瞄器(如"Microsoft IE或Netscape)即可监视其影像。

网络摄像机要将高清楚度的实时视频信息通过互联网传送到监控终端，因其信息量巨大，所以必需压缩。

通常人们采纳与MPEG-4算法相结合的计划来实现，不仅编程工作量大，而且产品的成本高。

本文所介绍的网络摄像机采纳专用的MPEG-4压缩芯片、以作为操作系统，不仅开发便捷、成本低廉，而且实时性好，适用范围广。

2.系统总体设计系统总体设计包括硬件设计和软件设计两部分。

这两部分工作是相互联系的，需要交错举行，系统设计是开发人员举行的工作，他们将系统设计阶段得到的目标系统的规律模型转换为目标系统的物理模型，该阶段得到工作成绩――系统设计解释书是下一个阶段系统实施的工作依据。

硬件设计模块主要包括微控制器模块、微控制器是将微型计算机的主要部分集成在一个芯片上的单芯片微型计算机。

微控制器出生于20世纪70年月中期，经过20多年的进展，其成本越来越低，而性能越来越强大，这使其应用已经无处不在，遍及各个领域。

例如电机控制、条码阅读器/扫描器、消费类、嬉戏设备、电话、HVAC、楼宇平安与门禁控制、工业控制与和白色家电(洗衣机、微波炉)等。

压缩编码模块、网络接口模块和相机控制模块四部分。

微控制器模块主要由主控芯片、DataFlash和SDRAM(1)组成。

其中，主控芯片是囫囵控制系统的核心，它负责囫囵系统的调度工作。

DataFlash里固化了嵌入式Linux内核、及其文件系统、应用软件和第1页共7页。

AT91RM9200(DKEK) VxWorks BSP

AT91RM9200(DK/EK) VxWorks BSP开发者指南AT91RM9200(DK/EK) VxWorks BSP (1)开发者指南 (1)1. 介绍: (1)2. 软件包安装: (2)3. BSP结构: (2)•逻辑结构 (2)•文件结构 (4)4. 编译与裁减ＢＳＰ (5)5. 硬件配置 (7)6.程序流程 (8)7. 程序说明 (8)1) 基本 BSP (8)2) 中断控制器驱动(intrCtl) (12)3) 时钟驱动(timer) (13)4) Uart 驱动(sio) (14)5) 网络驱动(end) (14)6) usb Host驱动(usb) (16)7) usb slave驱动(usbslave) (16)8) Display驱动(display) (18)9) CompactFlash卡驱动(cf) (20)10) 声音codec驱动(audio) (23)11) DataFlash卡驱动(dataflash) (25)12) MMC 卡驱动(mmc) (28)1. 介绍:本软件是基于ATMEL AT91RM9200 评估板(AT91RM9200DK 和 AT91RM9200EK) 的VxWorks 操作系统的BSP.它包含以下功能.1) AT91RM9200 高级中断控制器(AIC)2) AT91RM9200 系统时钟3) 2 个UART .4) 1 个10/100M 以太网口5) USB host (OHCI)接口.6) USB Salve 接口7) 1个 CompactFlash 接口8) 1个 Atmel DataFlash/MMC 接口.9) 1个 DAC3550A 音频输出接口.10) Epson s1d13806 显示接口.2. 软件包安装:本软件包有两部分组成.一部分是BSP(at91rm9200bsp.zip), 另一部分是范例项目(at91rm9200proj.zip).把at91rm9200bsp.zip 直接解压到Vxworks操作系统安装目录下的target/config目录下. 解压后会出现at91rm9200目录.把at91rm9200proj.zip 直接解压到Vxworks操作系统安装目录下的target/proj目录下. 解压后会出现at91rm9200目录.3. BSP结构:• 逻辑结构本软件包有两部分组成.一部分是BSP, 另一部分是范例项目.BSP 位于Vxworks操作系统安装目录下的target/config/at91rm9200.范例项目位于Vxworks安装目录下的target/proj/at91rm9200.启动Tornado后,打开workspace, target/proj/at91rm9200/at91.wsp.在这个workspace中包含了项目 at91rm9200.wpj ,每个项目有三个视图（Files, Vxworks,Build）.Files 视图列出了范例项目包含的文件，这些文件都是缺省的，基本上每一个项目都是一样的(参阅vxworks的手册)。

星光AT91RM9200开发板使用手册

中国电子开发网()星光AT91RM9200开发板使用手册用户手册CEDN2008‐4‐1在使用本文档的时候，如遇到问题请访问中国电子开发网的技术支持()目录星光AT91RM9200开发板使用手册 (3)0 结构示意图 (3)1 系统构成 (4)1.0 基本构成 (4)1.1 外部接口 (4)2 地址空间分配（系统reset之后） (4)3 外部中断分配 (5)4 跳线说明 (6)4.0 启动模式选择 (6)4.1 其他跳线（一般不必设置） (6)5 首次使用 (7)5.0 注意事项 (7)5.1 开发板板载启动代码 (7)5.2 开发板板载启动信息 (7)6 简单程序的调试 (8)6.0 调试工具 (8)6.1 AXD添加H‐JTAG支持 (8)6.2 调试过程 (9)7 将文件烧写到开发板 (12)7.0 将文件烧写到NOR FLASH (12)8 其他说明 (14)星光AT91RM9200开发板使用手册0 结构示意图图1、星光AT91RM9200开发板结构示意图1 系统构成1.0 基本构成1、处理器CPU: 型号AT91RM9200 封装272pin‐FBGA2、NOR FLASH: 型号SST39VF3201 封装48Pin‐TSOP 4M 总线宽带16bits3、NAND FLASH: 型号K9F1208U0C‐Y,P 封装48pin‐TSOP1 64M4、内存SDRAM: 型号HY57V281620 封装54pin‐TSOP 两片32M 总线宽带32bits 1.1 外部接口1、UART串口: 3个的串口（J3为4线，J4为2线(DEBUG)，J15为485串口）。

2、USB接口: 1个USB Host接口。

1个USB Device接口。

3、IIC接口: 用于IIC总线EEPROM。

4、SD/MMC接口: 用于SD/MMC卡。

5、CF卡接口: 1个CF卡。

6、CAN总线: 通过SPI总线扩展，MCP2515 CAN控制器。

基于AT91RM9200与LINUX2.6.26内核的嵌入式平台开发全过程

基于AT91RM9200与LINUX2.6.26内核的嵌入式平台开发全过程收藏一、ARM9+LINUX开发历程使用了51系列和MOTOROLA单片机若干年，觉得自己已经跟不上嵌入式发展的时代了。

决定开发一种新的硬件平台，综合比较了一下，觉得ARM9+LINUX模式不错。

先从头捋一遍32位嵌入式开发平台的流程：芯片选型——使用DXP画原理图（如果有可能买块开发板可以极快加快进度）——使用DXP 画ＰＣＢ图——芯片购买/PCB投板生产——芯片焊接——使用ADS编写简单硬件测试程序，调试硬件——搭建LINUX服务器，在服务器建立交叉编译环境——利用服务器和本机超级终端开发U-BOOT-1.3.4——利用U-BOOT-1.3.4的以太网FTP功能和服务器移植开发LINUX-2.6.26 内核——开发文件系统——开发驱动程序——应用程序开发，项目完基本成后回过头来想就是这个一个过程，中间走了不少弯路，在本博客中都有记载，很多问题有的也没有来得及记。

说干就干，时间安排如下：（1）5~7月硬件设计（芯片，型号，预测价格），已初步完成CPU：AT91RM9200,81SDRAM：MT48LC16M16A2TG-75IT（两片32MB*2）74*2FLASH：S29GL256N10TAI010（NOR型，32MB，存代码，写慢读快）57.52FLASH∶K9F2G08U0B（NAND256MB，预留存测试数据，写快读慢）41.1铁电存储器：FM24CL64（代替EEPROM24LC65，8KB）8.29以太网物理层控制器：DM9161E（100M/10M自适应）9.4从USB接口：用于与PC机通信主USB接口：用于后续移植LINUX时软件更新触摸屏驱动器：TSC2046（预留）液晶显示屏模块-TFT液晶显示接口（预留）（２）ADS+AXD+J-LINK调试过程目的是为了熟悉ARM开发流程,ADS开发环境,以便为将来U-BOOT的移植打下基础.由于网上资料不多,本步骤走了不少冤枉路,特总结在此,以便以后可以参考.容易步骤省略.安装ADS>>创建ADS工程>>添加所需要文件>>DEBUG SETTING,将程序的RO_Base设为0X200000则将程序导入A T91RM9200的片内16K的SRAM中运行，实践证明此时不需要管BMS引脚是高是低都能正常运行，也不需要进行REMAP；若将程序的RO_Base设为0X20000000则将程序导入片外64M的SDRAM中运行，此时程序导进SDRAM后需要SETMEM命令将SDRAM初始化，才能正常运行。

基于AT91RM9200微处理器的最小系统设计

研究Technology StudyI G I T C W 技术26DIGITCW2020.061 A RM 微处理器目前，在多个领域中都在使用ARM 微处理器，例如通信电子、智能工业、多媒体教育等。

根据相关数据统计，通用计算机的应用数据已经大大低于基于ARM 微处理器的设备应用数据。

故此，基于ARM 微处理器的开发应用已成为数字时代的应用技术潮流。

文章中主要介绍了基于AT91RM9200处理器的最小系统，其次介绍了ARM 芯片的外围接口的电路设计，并给出了相关器件选型。

2 硬件设计最小系统是最基本的电路，为了保证微处理器的工作可靠。

ARM 处理器最小系统的定义是确保ARM 处理器能够正常启动、运行的最小电路集合。

由微处理器AT91RM9200、电源电路、晶体振荡器电路、复位电路、NorFlash 、SDRAM 、RS232调试接口等电路组成最小嵌入式系统，其原理框图如图1所示。

图1 最小系统的框架图在本方案中，ARM 处理器选用ATMEL 公司AT91RM9200芯片，具有ARM920T 内核，带有MMU （Memory Management Unit ），工作时钟可达到180 MHz ，具有外部存储器扩展端口，具有外部中断控制器，支持以太网和USB 接口。

2.1 电源电路ARM 处理器I/O 电源3.3 V 推荐芯片LT1764AEQ-3.3#PBF V 推荐芯片，ARM 处理器内核电源1.8 V 推荐芯片TPS72518DCQ ，如图2所示。

2.2 复位电路低电平有效，300 ms 以上，模块正常运行时为高电平；本设计中的复位电路由FPGA提供。

图2 电源电路2.3 晶体振荡器电路存储系统运行所需的时钟和外设电路工作时所需的时钟由晶体振荡器电路提供。

本设计使用无源晶体作为时钟输入，即使掉电程序和数据都不会丢失；起振需要ARM 处理器内部PLL 锁相环电路配合，震荡起振。

设计中主时钟采用18.432 MHz 无源晶振，在ARM 芯片内部通过锁相环倍频至180 MHz 以上，作为ARM 处理器的工作时钟，慢速时钟采用32.768 kHz 无源晶振，为ARM 处理器的慢速外设提供时钟。

AT91RM9200DK U-Boot Flash Programming Solutions

AT91RM9200DK U-Boot Flash ProgrammingSolutionsIntroductionThe AT91RM9200DK Development Board is provided with a default boot program in its external Flash memory. This boot program, called U-Boot, is used by the AT91RM9200DK to boot after reset. The U-Boot performs initialization of the AT91RM9200DK, provides user interface via the Serial Debug Port and allows appli-cation download through the Serial Debug Port or Ethernet.This Application Note aims at providing solutions when the U-Boot program contained in the external Flash of AT91RM9200DK Development Board has been deleted. Two ways of reprogramming the Flash memory are described in this Application Note; the method selected depends on whether the user has a Slingshot™ JTAG/ICE interface. If this interface is not being used, then the external Flash is reprogrammed using the internal BootROM (embedded on the AT91RM9200 version 58A07F).AT91 ARM®Thumb®MicrocontrollersApplication Note6041A–ATARM–01/042AT91RM9200DK U-Boot Application Note6041A–ATARM–01/04U-Boot SoftwareFeatures The main features of the U-Boot software embedded in the AT91RM9200DK Develop-ment Kit are:•Standalone primary bootstrap •Small footprint •OS-independent •Auto-boot and interactive modes •Command line interface •Non-volatile environment variables •Flash programming capability •DataFlash programming capability (only available in latest Open Source download)•Download through serial interface (Kermit protocol)•Download through Ethernet (tftp)•Integrated bootp •Scripting capabilityOrganization To optimize the use of resources, U-Boot is made up of three parts:•A primary bootstrap •A de-compression executable • A gzip-compressed binary executable called the U-Boot ImageThe primary bootstrap is concatenated to the de-compression executable into one sin-gle file called the boot image and must reside in the AT91RM9200DK Flash on NCS0 ataddress 0x1000_0000.The primary bootstrap is a simple assembly code routine that sets up the system andputs it into an operational state. More specifically, it starts the high-speed clocks of theCPU and programs the on-chip memory controller to define the memory layout. Whenthese steps are completed, the primary bootstrap gives control to the de-compressionexecutable.The de-compression executable is an optimized version of the gunzip program. It de-compresses the gzip-compressed image of U-Boot into RAM, and jumps to it. The loca-tion of the binary executable in RAM is defined at link time.3AT91RM9200DK U-Boot Application Note6041A–ATARM–01/04Figure 1. Flash Mapping0x1000_0000Boot Image24 KbytesEnvironment Variables 8 Kbytes0x1000_E0000x1000_60000x1001_0000Free32 KbytesU-BootgzippedImage64 Kbytes0x1002_00004AT91RM9200DK U-Boot Application Note6041A–ATARM–01/04Reprogramming the External Flash on the AT91RM9200DK Development Board For Users of SlingshotJTAG/ICE Interface andMULTI ®2000The procedure for reprogramming the Flash described here is applicable to users of the AT91RM9200DK Development Board who have the Green Hills ® Slingshot JTAG/ICE interface and MULTI2000.Hardware and SoftwareRequirements •UBootFlashProgramming.zip file provided with this Application Note •Green Hills Slingshot JTAG/ICE interface •Green Hills MULTI2000 (V3.6.1 or higher) running on your PC •A serial cable (null modem)•HyperTerminal running on your PC application (1115200, 8, N, 1)Connecting theAT91RM9200DK to the HostPC 1.Connect the AT91RM9200DK to the Host PC using the serial cable through the Serial Debug Port on the A T91RM9200DK and the serial COM port on the Host PC. Open a HyperT erminal session with the following configuration: 115200 bitrate, 8-bit data length, No parity bit, 1 stop bit and No flux control.2.Connect the Slingshot JT AG/ICE Interface to the A T91RM9200DK through theJTAG/ICE Interface connector and to the PC through the USB Port.Launching the MULTI2000 3.Extract the AT91RM9200 Getting Started Software Package file calledAT91RM9200-GettingStarted-GHS3_6-1_1.exe , available in the UBootFlash-Programming.zip file provided with this Application Note.unch the MULTI2000 Project Manager and open the project Getting-Started.bld. This is available in the software package, extracted to the followingdirectory path C:\UBootFlashProgramming\AT91RM9200-GettingStarted-GHS3_6-1_1\A T91RM9200-GettingStarted\compil.5.Select the project basic_flash.bld by double-clicking on it. Build it and check ifbuild was succesful.6.Power-up and reset the AT91RM9200DK Development Board.Configuring the Connection to the AT91RM9200DK This is one of the most important steps in the procedure. As the Flash has been com-pletely erased, a standard initialization that would normally configure the External BusInterface, the Remap and the PLLs is not performed on the AT91RM9200DK. To carryout the initialization correctly, a Target Setup Script file (extension .dbs) must be used.The file, named mpserv_dk9200_PLL.dbs, is provided with this Application Note. Youare strongly advised to use it.To proceed:7.Click on the Connect button to open the Connection Chooser window:5AT91RM9200DK U-Boot Application Note6041A–ATARM–01/048.In the Connection Chooser window, select the ARM ®9 Green Hills Probe ™ Con-nection (mpserv):9.Edit the selected Connection Method:10.In the Slingshot Connection Editor window, select the Target Setup Script file thatinitializes the AT91RM9200DK correctly. It is very important to use the filempserv_dk9200_PLL.dbs provided with this Application Note:6AT91RM9200DK U-Boot Application Note6041A–ATARM–01/04Launching the Debugger 11.Click on the Debug button to run the debugger:12.In the debugger environment, click on the Step button to download thebasic_flash project:13.In the debugger environment, switch to the command pane:Loading the LoaderApplication The next step is to download the loader.bin application. This application is used to download a binary file from a HyperTerminal session through the Serial Debug Portusing the Xmodem protocol. The loader.bin file to download is available in the the soft-ware package extracted at the beginning of the procedure and available in the directory C:\UBootFlashProgramming\AT91RM9200-GettingStarted-GHS3_6-1_1\AT91RM9200-GettingStarted\Flash. See “Launching the MULTI2000” on page 4.14.Download the loader.bin application in the internal RAM at address 0x200000 bywriting the following command in the command pane window (prompt MULTI>):MULTI> memload raw C:\UBootFlashProgramming\AT91RM9200-GettingStarted-GHS3_6-1_1\AT91RM9200-GettingStarted\Flash\loader.bin 0x20000015.Set the Program Counter (pc) at the beginning of the downloaded loader.binapplication and run from here:MULTI> target reg pc 0x200000MULTI> target runLoading U-Boot The loader application is now running on the AT91RM9200DK and is ready to downloada binary application file through the Serial Debug Port using the Xmodem protocol on a HyperTerminal session.16.Download the u_boot.bin binary file using the Xmodem protocol. This file isavailable in the UBootFlashProgramming.zip file provided with this ApplicationNote under the directory path C:\UBootFlashProgramming\binary.7AT91RM9200DK U-Boot Application Note 6041A–ATARM–01/04In the HyperTerminal session, send the file u_boot.bin using the Xmodem protocol.At the end of the Xmodem transfer, a new prompt is displayed in the HyperTerminal window:Uboot>The U-Boot is now running on the AT91RM9200DK.This Boot program can now be used to download files to the SDRAM through the Serial Debug Port using the Kermit protocol with a HyperTerminal session. It is then copied to the Flash.Downloading U-Boot BinaryFiles The last step is to download the primary bootstrap, boot.bin, and the gzip-compressed U-Boot image, u-boot.gz. These two files are available in the UBootFlashProgram-m i ng.z i p fi l e pr o v i d e d w i t h t hi s A p pl i c a t io n N o te in th e d i r e c to r y C:\UBootFlashProgramming\binary.17.The first file to load is the boot image “boot.bin ”.Uboot> loadb 20000000## Ready for binary (Kermit) download …## Start Addr =0x20000000The boot image is now loaded in SDRAM. The following command copies the SDRAM (0x20000000) to Flash(0x10000000):Uboot> protect off 10000000 10005fffUnprotect 3 sectorsUboot> erase 10000000 10005fffErase Flash from 0x10000000 to 0x10005fff...Erasing sector 0 ... ok.Erasing sector 1 ... ok.Erasing sector 2 ... ok.done.Erased 3 sectors.Uboot> cp.b 20000000 10000000 5FFFCopy to flash… done.Uboot> protect on 10000000 10005FFFProtected 3 sectorsUboot>18.Once the primary bootstrap has been loaded, the U-Boot gzipped image can becopied into Flash. The file to load is the uboot gzipped image “u-boot.gz ”:Uboot> loadb 20000000## Ready for binary (Kermit) download …## Start Addr =0x20000000Uboot> protect off 10010000 1001ffffUnprotect 1 sectorsUboot> erase 10010000 1001ffffErase Flash from 0x10010000 to 0x1001ffff...8AT91RM9200DK U-Boot Application Note6041A–ATARM–01/04Erasing sector 8 ... ok.done.Erased 1 sectors.Uboot> cp.b 20000000 10010000 FFFFCopy to flash… done.Uboot> protect on 10010000 1001FFFFProtected 1 sectorsUboot>19.The U-Boot has been upgraded. Reboot your board.9AT91RM9200DK U-Boot Application Note6041A–ATARM–01/04Using the InternalBootROM The procedure for reprogramming the Flash described here is applicable to users of theAT91RM9200DK Development Board who do not have a Green Hills Slingshot JTAG/ICE Interface. The solution presented here uses the Internal BootROM of the AT91RM9200.After reset, the AT91RM9200DK boots from the external Flash memory by default (BMS high during reset). To boot using the embedded Boot ROM program (on-chip boot mode with BMS low during reset), it is mandatory to remove the R159 resistor from the AT91RM9200DK development board temporarily.Hardware and SoftwareRequirements •UBootFlashProgramming.zip file available with this Application Note •A serial cable (Null modem)•HyperTerminal running on your PC application (1115200,8,N,1)Connecting theAT91RM9200DK to the HostPC 1.Connect the AT91RM9200DK to the Host PC using the serial cable through the Serial Debug Port on the A T91RM9200DK and the serial COM port on the Host PC. Open a HyperT erminal session with the following configuration, 115200 bitrate, 8-bit data length, No parity bit, 1 stop bit and No flux control.Loading the Loader Application2.Download the loader.bin application. This application is used to download abinary file from a HyperTerminal session through the Serial Debug Port using the Xmodem protocol.3.Extract the AT91RM9200 Getting Started Software Package file calledAT91RM9200-GettingStarted-GHS3_6-1_1.exe , available on the UBootFlash-Programming.zip file provided with this Application Note. The loader.bin file to download is available in the software package extracted to the following directory path C:\UBootFlashProgramming\AT91RM9200-GettingStarted-GHS3_6-1_1\A T91RM9200-GettingStarted\Flash.4.Power-up and reset the AT91RM9200DK Development Board.The Internal Boot Program runs and waits for downloading an application code into the internal SRAM via Xmodem protocol through the Serial Debug Port (DBGU). It then branches to the application entry point at the first address of the SRAM.5.On the HyperTerminal session, send the file loader.bin using Xmodem protocol.Loading U-Boot The loader application is now running on the AT91RM9200DK and is ready to downloada binary application file through the Serial Debug Port using the Xmodem protocol on a HyperTerminal session.6.Download the u_boot.bin binary file using the Xmodem protocol. This file isavailable available in the UBootFlashProgramming.zip file provided with this Application Note under the following directory path C:\UBootFlashProgramming\binary.In the HyperTerminal session, send the file u_boot.bin using Xmodem protocol. At the end of the Xmodem transfer, a new prompt is displayed in the HyperTerminal window:Uboot>The UBoot is now running on the AT91RM9200DK.This Boot program can be used to download files to the SDRAM through the Serial Debug Port using the Kermit protocol with a HyperTerminal session. It is then copied to the Flash.10AT91RM9200DK U-Boot Application Note6041A–ATARM–01/04Downloading U-Boot BinaryFiles The last step is to download the primary bootstrap, boot.bin, and the gzip-compressed U-Boot image, u-boot.gz. These two files are also available in the UBootFlashProgram-m i ng.z i p fi l e pr o v i d e d w i t h t hi s A p pl i c a t io n N o te in th e d i r e c to r y C:\UBootFlashProgramming\binary.7.The first file to load is the boot image “boot.bin ”.Uboot> loadb 20000000## Ready for binary (Kermit) download …## Start Addr =0x20000000The boot image is now loaded in SDRAM. The following command copies the SDRAM (0x20000000) to Flash(0x10000000).Uboot> protect off 10000000 10005fffUnprotect 3 sectorsUboot> erase 10000000 10005fffErase Flash from 0x10000000 to 0x10005fff...Erasing sector 0 ... ok.Erasing sector 1 ... ok.Erasing sector 2 ... ok.done.Erased 3 sectors.Uboot> cp.b 20000000 10000000 5FFFCopy to flash… done.Uboot> protect on 10000000 10005FFFProtected 3 sectorsUboot>8.Once the primary bootstrap has been loaded, the U-Boot gzipped image can becopied into Flash. The file to load is the uboot gzipped image “u-boot.gz ”:Uboot> loadb 20000000## Ready for binary (Kermit) download …## Start Addr =0x20000000Uboot> protect off 10010000 1001ffffUnprotect 1 sectorsUboot> erase 10010000 1001ffffErase Flash from 0x10010000 to 0x1001ffff...Erasing sector 8 ... ok.done.Erased 1 sectors.Uboot> cp.b 20000000 10010000 FFFFCopy to flash… done.Uboot> protect on 10010000 1001FFFFProtected 1 sectorsUboot>The U-Boot has been upgraded.11AT91RM9200DK U-Boot Application Note6041A–ATARM–01/049.Set the R159 resistor on the AT91RM9200DK to boot from the external Flashmemory. Reboot your board.Printed on recycled paper.Disclaimer: Atmel Corporation makes no warranty for the use of its products, other than those expressly contained in the Company’s standard warranty which is detailed in Atmel’s Terms and Conditions located on the Company’s web site. The Company assumes no responsibility for any errors which may appear in this document, reserves the right to change devices or specifications detailed herein at any time without notice, and does not make any commitment to update the information contained herein. No licenses to patents or other intellectual property of Atmel are granted by the Company in connection with the sale of Atmel products, expressly or by implication. Atmel’s products are not authorized for use as critical components in life support devices or systems.Atmel CorporationAtmel Operations2325 Orchard Parkway San Jose, CA 95131, USA Tel: 1(408) 441-0311Fax: 1(408) 487-2600Regional HeadquartersEuropeAtmel SarlRoute des Arsenaux 41Case Postale 80CH-1705 Fribourg SwitzerlandTel: (41) 26-426-5555Fax: (41) 26-426-5500AsiaRoom 1219Chinachem Golden Plaza 77 Mody Road Tsimshatsui East Kowloon Hong KongTel: (852) 2721-9778Fax: (852) 2722-1369Japan9F, Tonetsu Shinkawa Bldg.1-24-8 ShinkawaChuo-ku, Tokyo 104-0033JapanTel: (81) 3-3523-3551Fax: (81) 3-3523-7581Memory2325 Orchard Parkway San Jose, CA 95131, USA Tel: 1(408) 441-0311Fax: 1(408) 436-4314Microcontrollers2325 Orchard Parkway San Jose, CA 95131, USA Tel: 1(408) 441-0311Fax: 1(408) 436-4314La Chantrerie BP 7060244306 Nantes Cedex 3, France Tel: (33) 2-40-18-18-18Fax: (33) 2-40-18-19-60ASIC/ASSP/Smart CardsZone Industrielle13106 Rousset Cedex, France Tel: (33) 4-42-53-60-00Fax: (33) 4-42-53-60-011150 East Cheyenne Mtn. Blvd.Colorado Springs, CO 80906, USA Tel: 1(719) 576-3300Fax: 1(719) 540-1759Scottish Enterprise Technology Park Maxwell BuildingEast Kilbride G75 0QR, Scotland Tel: (44) 1355-803-000Fax: (44) 1355-242-743RF/AutomotiveTheresienstrasse 2Postfach 353574025 Heilbronn, Germany Tel: (49) 71-31-67-0Fax: (49) 71-31-67-23401150 East Cheyenne Mtn. Blvd.Colorado Springs, CO 80906, USA Tel: 1(719) 576-3300Fax: 1(719) 540-1759Biometrics/Imaging/Hi-Rel MPU/High Speed Converters/RF DatacomAvenue de Rochepleine BP 12338521 Saint-Egreve Cedex, France Tel: (33) 4-76-58-30-00Fax: (33) 4-76-58-34-80Literature Requests/literature6041A–ATARM–01/04© Atmel Corporation 2004. All rights reserved. Atmel ® and combinations thereof are the registered trademarks of Atmel Corporation or its subsidiaries. Green Hills ® and MULTI ® are the registered trademarks, and Slingshot ™ and Green Hills Probe ™ are the trademarks of Green Hills Software, Inc. ARM ® is the registered trademark of ARM Ltd. Other terms and product names may be the trademarks of others.。

基于AT91RM9200和嵌入式Linux的I2C总线驱动程序

寄存器（ＴｗＩ—ＣｗＧＲ）中的编程值产生时钟。该寄
◇）＠＠＠激存器定义ＴｗｃＫ信号，使接口适应宽范围时钟。 ∈Ⅺ 广
Ｒ～形１ｔｃｎ｛Ｒ
ｋ＼ｗ嘲ｅＴＨＲ
图２主机发送模式
．
在ＡＴ９ｌＲＭ９２００中，Ｔｗｌ支持ｌ、２或３字节机发送和接收为例说明ＴｗＩ的工作时序，如图２。
的从机内部地址，因选择ＡＴ２４Ｃ５１２芯片为从机，
２基于ＡＴ９１ＲＭ９２００的１２Ｃ总线工作时序图
ＡＴ９１ＲＭ９２００下，ＴｗＩ具有主机发送和主机接收２种工作模式。主机模式下，ＴｗＩ控制寄存器
（ＴＷＬＣＲ）。可配置为接口，根据时钟波形发生器
如图１，ＴｗＤ与ＴＷＣＫ为双向线，通过源正极或上拉电阻连接。当总线空闲时，两线为高。连
Ｋ’
ｚ’＼＼ｗＨｔｃＴＨＲ
【５】周剑波。基于ＦＰＧＡ和嵌入式Ｌｉｎｕｘ的网络视频采集处
理系统研究【Ｄ】．北京：北京科技大学，２Ｑ０６．
·９３·
万方数据
主机初始化Ｓｔａｒｔ状态后，向主机模式寄存器
其容量为６４ＫＢ，所以选２字节的从机地址。以主 ‘（ＴｗＩ—ＭＭＲ中ＤＡＤＲ）发送７位从机地址。其后
收稿日期｝２００７—０４—２６ｌ修回日期：２００７一０６一０８作者简介：张圣华（１９８２一），男，河北人，硕士研究生，从事嵌入式操作系统研究与设计． ·９２·
动程序进行分析和设计，通过１２Ｃ总线实现实时、高效、稳定的数据传输。
僦脍１基于ＡＴ９１ＲＭ９２００的１２Ｃ总线原理框图
Ｉ坐呈璺！ｇ！Ｉ
—忑二＝，
ＴＷＣＫＴＷＤ
陌ｎ：者薪习ｈ
ＭｃＫ。－
图１基于ＡＴ９１ＲＭ９２００的１２Ｃ总线原理框图
接到总线的输出流水线须有开漏或开集来执行线的功能。ＴＷＤ与ＴｗＣＫ引脚可与ＰＩＯ线复用。为使能ＴＷＩ，将对ＰＩＯ控制器编程，即将ＴｗＤ与ＴｗｃＫ指定为外设线，将其定义为开漏。为使微处理器与外设间由１２Ｃ总线完成通信，须配置电源管理控制器（ＰＭＣ），使ＴｗＩ时钟和ＴｗＩ接口与高级中断控制器（ＡＩＣ）连接。在系统应用模式中，只需实现ＡＴ９ｌＲＭ９２００与ＥＥＰＲＯＭ通信，对中断无要求，则在配置ＴＷＩ前需对ＡＩＣ编程，禁用中断。

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以太网控制器在嵌入式系统中有两种方式：一种是内部集成（不需要额外即
的以太网控制芯片）另一种是通过以；太网接Ｅ控制芯片（Ｌｌ如ＡＮ９Ｃ６ｌ９、ＲＴ一Ｌ
２ＭＡ控制送出去。接收数据帧：首先通过底层芯片将
‘ ＢＲ、１ＴＣＤ）…．．按迭字节寄存器ＤＭＡ接收寄存器（ＳＡＫ …… 一面起始地址寄存器ＰＴＴ）页（ＳＯＰ）ＰＴ …… …．停止寄存器页面（ＵＲＣＲ）～……一当前页面寄存器（ＮＲＢｙ）…… …一界指针寄存器边（Ｂ …… ……．收字节寄存器ＲＣ）接
制器的以太网接口驱动程序设计来系统地Ｊ【上数据帧的控制功能提供ＭＩＭｅｉ硐Ｉ（ｄａ分析以太网控制器和物理层芯片的驱动程ｌＩｄｐｎｅ￣ｌｅｆｃ）标准管理通信接ｎｅｅｄｎｉｒｅｎａ
ｎ。但它本身不具有直接从网上收发数据的能力必须接台物理层数据传输１Ａ９Ｒ２０芯片Ｄ１１Ｍ９６来完成对网上数据的接Ｔ１Ｍ９０以太网控制器及物ｆ理层芯片Ｄ９６工作原理Ｍ１１『收解码和敖据帧编码发送任务根据圈１，可以看出ＭＡＣ层是通过ＤＭＡ控制方式来接手发送和接收数据，１１Ａ１Ｍ９０融控制器… ．Ｔ９Ｒ２０ＤＭＡ直接通过ＡＳＢ总线与存储器进行通Ａ１Ｍ９０是由Ａｎ公司针对通ｆＴ９Ｒ２０ｔｍｌ信。ＥＭＡｃ（以太ｒ控制器】蝴与物理层芯片信领域，系统控制推出的一种基于
．
序设计原理和实现方法。
ＡＲＭ９０２Ｔ
前言
随着嵌人式系统在工程应用和人们生括中的运用越来越广．对它的分析研究也越来越多，嵌入式系统与通信、网络技术的结合可以极大地增强网络的智能化与灵活性，拓展通信功能，从而实现各
块即以太嗣控制器部分，由它集台物理层恃输芯片Ｄ１１Ｍ９６殛相应的驱动程序来通过ＤＭＡ控制方式完成对网上敖据帧的读
平台Ｌ，针对相同的底屠芯片需要编辑不Ｊ写。同的驱动程序ｓ而相同的操作系统在不同『１２．鼬太网接口控制器的工作原理
的硬件平台上也需要编辑不同的驱动程序。
维普资讯
基于ＡＴ１９ＲＭ９０微控制器的２０
以太网接口驱动程序设计
程佳佳宋晓红张宁北京交通大学计算机网络管理中１０４０４０
种通信系统之间的互联互通根据嵌人式内核可裁减、硬件和驱动程序紧密结合的特点，不同的操作系统在同一个硬件
图３以太网控制器ＤＡ通道数据传输原理图、Ｍ
图２以太网控制器内部功能模块图、
ＤＭＡ发送寄存器（ＰＲ）Ｔｓ …… …～发送页面起始寄存器
之间通信是通过ＰＯ口来实现。在实际的Ｉ驱动程序编写中可以通过设置ＰＩ口的Ｏ
ＰＤＲ（Ｉｉａｌｅｉｅ）来配置使ＰＯＤｓｂｅＲｇｓｒｔ
在编写躯动程序之前首先分析一下它
而以太网通信接口驱动程序通常是嵌入式
的硬件电路．以太网接Ｉ部分主要分成两１：系统所必需的，有时为了各种原因，如安ｌ个部分：”．以太嗣控制器ｔ）物理层实现．２全性或实时性等考虑需要更换其它操作系『数据帻的发送和接收芯片统，选时原有的以太网驱动程序就不再有ＡＴ９１ＲＭ９０２０本身带有以太研控制用，必须更改。本文就ＡＩ，２０Ｔ９ＰＭ９０撇控１器，兼容ＩＥ８２３议标准．具有对ＥＥ０．
据帧的ＭＡＣ地址，帧头信息和ＣＲＣ校验码是否正确，如果不正确就册除掉，０正确通过ＤＭＡ通道将数据拷贝到接收缓
采用ＲＭＩ还是ＭＩ控制方式视硬件ＩＩ电路设计而定，如今大多采用ＲＩ（简ＭＩ精
。
存区。这个过程涉及到复杂的存储区管
维普资讯
ＣＮｌ吃Ｊ＝ｏＴＵｒＫ
＝
ＭＥ啪ＲＹ
Ｕ＾
Ｃ
１６ＩＢｔＩ．Ｉ１２ｙＩ｝１｝ｔＦＯ ¨ ￣ｌ８￣
＾
卜
Ｄ＾＾Ｔ
ＳＳＴＥＭＹ ∞ ，ＨＯ
￡ＭｏＲＹ
２１Ｄ．ＭＡ通道数据传输控制原理
图３描述了数据帧是如何由ＤＭＡ通道来进行数据传输，网上接收到的数据帧通过ＤｌｌＭ９６解码后传输到ＦＦＩＯ，然
能ＭＤＣ（管理数据控制器），ＭＤＩ（Ｏ管
理数据输入输出）Ｅ０（，Ｆ１０使能全双工１００Ｍ以太网）采用ＭＩＲＩ，ＩＭＩ／方式选择等
１Ｉ２
接收到的数据帧传输到２８字节的接收ＦＦ中，ＩＯ当一帧数据接收完以后，检验数
理，必须结合了解存储区之间的关系。
型ＭＩ）方式，只需连两根线（ＸＤ／，ＩＲ０１
图４、ＤＭＡ控制器中发送、接收核心寄存器
Ｔｘ／）Ｄ０１，简洁方便。
１３以太网控制器的功能及对发送和．
接收数据帧的控制原理