嵌入式军用PDA系统中触摸屏的研究与实现
摘要
本文研究、设计和实现了基于PXA255处理器军用PDA系统触摸屏的功能。该模块的主要控制器件是TI公司生产的TSC2301芯片,TSC2301支持I2S/AC97标准20位立体声编码/解码、支持可编程采样率、输入输出增益和数字音响处理功能,同时集成了触摸屏控制和4×4键盘控制功能。TSC2301通过SPI总线与外围设备进行数据交换。
本系统触摸屏模块采用4W四线电阻触摸屏,当触笔或手指触摸屏幕时,它产生X与Y方向的两组模拟信号,TSC2301对这两组信号进行AD转换产生相应的数字信号,而后通过SPI总线从SPI接口传送给主控CPU——PXA255,从而实现触摸屏功能。
主控CPU对TSC2301的控制是通过把相关命令字写入它内部寄存器的方式来实现的。本文通过对TSC2301内部寄存器,AD转换方式、编码格式、通信协议等特点的研究,详细说明了TSC2301的工作模式。并介绍了系统中该模块的硬件电路设计、主从处理器通信和系统对该模块的初始化设置、驱动程序等,通过以上这些工作,实现了军用PDA系统中所设计的触摸屏功能,经过测试,该模块运行稳定,触摸屏性能良好。
This thesis mainly focuses on studying, design and implementation of a Touch Screen Module of military PDA system based PXA255. The dominated controller of it is TSC2301 which is manufactured by TI Corporation. It contains a complete 12-bit A/D resistive touch screen converter (ADC) including drivers, touch pressure measurement capability, keypad controller, and 8-bit D/A converter (DAC) out-put for LCD contrast control. A register-based architecture eases integration with microprocessor-based systems through a standard SPI bus. All peripheral functions are controlled through the registers and onboard state machines.
The module of PDA system selects a resistive 4-wire touch screen. When the touch panel is pressed or touched, there are two signals-X and Y, must be generated. They are inputted into TSC2301 and are converted to digital signal, then are transmitted to PXA255. After this process the touch screen function can be implemented.
All peripheral functions are controlled through writing command words into TSC2301 internal register. Through studying register, AD/DA, data format, communication protocol of TSC2301, the work module of TSC2301 is introduced. In addition, the design of module circuit, register configuration, driver etc. in the system are discussed. And touch screen function is reliable after system debugging.
本系统触摸屏模块采用4W四线电阻触摸屏,当触笔或手指触摸屏幕时,它产生X与Y方向的两组模拟信号,TSC2301对这两组信号进行AD转换产生相应的数字信号,而后通过SPI总线从SPI接口传送给主控CPU——PXA255,从而实现触摸屏功能。
主控CPU对TSC2301的控制是通过把相关命令字写入它内部寄存器的方式来实现的。本文通过对TSC2301内部寄存器,AD转换方式、编码格式、通信协议等特点的研究,详细说明了TSC2301的工作模式。并介绍了系统中该模块的硬件电路设计、主从处理器通信和系统对该模块的初始化设置、驱动程序等,通过以上这些工作,实现了军用PDA系统中所设计的触摸屏功能,经过测试,该模块运行稳定,触摸屏性能良好。
This thesis mainly focuses on studying, design and implementation of a Touch Screen Module of military PDA system based PXA255. The dominated controller of it is TSC2301 which is manufactured by TI Corporation. It contains a complete 12-bit A/D resistive touch screen converter (ADC) including drivers, touch pressure measurement capability, keypad controller, and 8-bit D/A converter (DAC) out-put for LCD contrast control. A register-based architecture eases integration with microprocessor-based systems through a standard SPI bus. All peripheral functions are controlled through the registers and onboard state machines.
The module of PDA system selects a resistive 4-wire touch screen. When the touch panel is pressed or touched, there are two signals-X and Y, must be generated. They are inputted into TSC2301 and are converted to digital signal, then are transmitted to PXA255. After this process the touch screen function can be implemented.
All peripheral functions are controlled through writing command words into TSC2301 internal register. Through studying register, AD/DA, data format, communication protocol of TSC2301, the work module of TSC2301 is introduced. In addition, the design of module circuit, register configuration, driver etc. in the system are discussed. And touch screen function is reliable after system debugging.
引文
[1] Intel? DBPXA250 and DBPXA210 Development Platform for Intel? Personal Internet Client Architecture July 2002
[2] Manuel Roman et al. Integrating PDAs into Distributed System: 2K and PalmORB,Processing First International Symposium on Handleld and Ubiqutous Computong,HUC’99,Karlsruhe,Germany,September 1999,PP137~149.
[3] Intel?PXA255 Processor Developer’s Manual,March 2003
[4] Texas Instruments TSC2301 Developer’s Manual,August 2003
[5] 陶玉玲. 触摸屏技术及其发展. 厦门科技,2002,6
[6] Steve Furber 著,田泽等译,《ARM SOC 体系结构》,北京航空航天大学出版社,2002.1
[7] 杜春雷编著,《ARM 体系结构与编程》,清华大学出版社,2003.2
[8] 李宏等编著,《液晶显示器件应用技术》,机械工业出版社,2004.2
[9] 沈绪榜,MPP 嵌入式计算机设计,清华大学出版社,1999 年 4 月,第一版
[10] 康宝祥,栾贵兴,RISC 体系结构及其实现技术,科学出版社,1996.1
[11] 周毓林,宁杨 等。《Windows CE.net 内核定制及应用开发》 北京:电子工业出版社,2005,3
[12] Microsoft Corp. Windows CE.net Help Control Version 4.74 8702,2003,5
[13] Intel DBPXA250 Development Platform Schematic Diagram,Intel,2002
[14] 魏忠,张勇,嵌入式开发详解,电子工业出版社 2003,1
[15] 毛德操,胡希明,《嵌入式系统——采用公开源码和 StrongARM/XSCALE 处理器》,浙江大学出版社,2004,5
[16] Wayne Wolf 著,孙玉芳,梁彬等译,《嵌入式计算机设计原理》,机械工业出版社,2002 年 2 月第一版
[17] Intel Corporation. 3Volt Intel StrataFlash Memory 28F128J3A, Data Sheet,2003.3
[18] Samsung Corporation. 128Mbit SDRAM 2M*16Bit*4Banks Synchronous DRAM LVTTL, Revision 0.0, Aug.1999
[19] 高鹏,《电路设计与制版Protel 99 入门与提高》,人民邮电出版社,2002 年 7月
[20] 阎利平,《C 语言基础教程》,电子工业出版社,2001 年 2 月
[21] 何立民,《MCS-51 系列单片机系统设计系统配置和接口技术》,北京航空航天大学出版社,2001,2
[22] 马忠梅等,《单片机的 C 语言应用程序设计》,北京航空航天大学出版社,1997,3
[2] Manuel Roman et al. Integrating PDAs into Distributed System: 2K and PalmORB,Processing First International Symposium on Handleld and Ubiqutous Computong,HUC’99,Karlsruhe,Germany,September 1999,PP137~149.
[3] Intel?PXA255 Processor Developer’s Manual,March 2003
[4] Texas Instruments TSC2301 Developer’s Manual,August 2003
[5] 陶玉玲. 触摸屏技术及其发展. 厦门科技,2002,6
[6] Steve Furber 著,田泽等译,《ARM SOC 体系结构》,北京航空航天大学出版社,2002.1
[7] 杜春雷编著,《ARM 体系结构与编程》,清华大学出版社,2003.2
[8] 李宏等编著,《液晶显示器件应用技术》,机械工业出版社,2004.2
[9] 沈绪榜,MPP 嵌入式计算机设计,清华大学出版社,1999 年 4 月,第一版
[10] 康宝祥,栾贵兴,RISC 体系结构及其实现技术,科学出版社,1996.1
[11] 周毓林,宁杨 等。《Windows CE.net 内核定制及应用开发》 北京:电子工业出版社,2005,3
[12] Microsoft Corp. Windows CE.net Help Control Version 4.74 8702,2003,5
[13] Intel DBPXA250 Development Platform Schematic Diagram,Intel,2002
[14] 魏忠,张勇,嵌入式开发详解,电子工业出版社 2003,1
[15] 毛德操,胡希明,《嵌入式系统——采用公开源码和 StrongARM/XSCALE 处理器》,浙江大学出版社,2004,5
[16] Wayne Wolf 著,孙玉芳,梁彬等译,《嵌入式计算机设计原理》,机械工业出版社,2002 年 2 月第一版
[17] Intel Corporation. 3Volt Intel StrataFlash Memory 28F128J3A, Data Sheet,2003.3
[18] Samsung Corporation. 128Mbit SDRAM 2M*16Bit*4Banks Synchronous DRAM LVTTL, Revision 0.0, Aug.1999
[19] 高鹏,《电路设计与制版Protel 99 入门与提高》,人民邮电出版社,2002 年 7月
[20] 阎利平,《C 语言基础教程》,电子工业出版社,2001 年 2 月
[21] 何立民,《MCS-51 系列单片机系统设计系统配置和接口技术》,北京航空航天大学出版社,2001,2
[22] 马忠梅等,《单片机的 C 语言应用程序设计》,北京航空航天大学出版社,1997,3