| In recent years, the rapid development of digitization technology centering on computer, chip technology and software engineering, greatly boost the research of embedded technology. Powerful embedded processor and excellent embedded operating system have been developed successively, which make the application of embedded system more and more widespread and contain each aspect of national economic construction. Embedded operating system runs on embedded processor, which can dispatch all tasks, manage the processor and other hardware devices. Embedded operating system shields the bottom details and affords the unified programming interfaces for users. This method enhances the product development efficiency.Embedded systems include embedded processors and embedded operating system. Embedded processors and the related functional expansion of the system's circuit constitute the hardware platform. Embedded operating systems include the bottom-driven software associated with hardware, system kernel, device driver, communication protocols, a graphical interface, standardization browser and so on. Embedded operating system runs on the embedded processor. Embedded operating system administers the processor and other hardware equipment in the bottom of processor, and it operates all application procedures. It shields the bottom of the details to provide a unified user interface. Application developers only need to split the application into several independent modules for system development. This has greatly simplified the application design, shortened the development cycle, reduced repeating work, improved the efficiency of product development and improved the efficiency of knowledge innovation.As a basic electronic equipment, signal generators are used widely in both teaching and research area, or in engineering technical support. Carrying on study deeply in signal generating from theory to technology has a positive meaning either in terms of teaching and research perspective, or from the engineering point of view of security services. With the continuous progress in computer technology and microelectronics technology, arbitrary waveform generator (AWG), which is a new type of signal generator, was invented. Direct Digital Synthesis (DDS) is a new method of frequency synthesis, which is a revolution in the field of frequency synthesis. With the development of digital intergrated circuits'technology and microelectronic technology, direct digital frequency synthesis technology is increasingly revealing its advantages. Arbitrary waveform generator on a basis of DDS technology has a series of particular virtues, including stable and accurate frequency of output, high quality waveform and wide bandwidth, which is an important research direction of AWG。This paper mainly carried on design and studying for the development of man-machine control system for AWG..Firstly the thesis describes several aspects of DDS in detail. It concerned basic theory, primary architecture, main features, etc. Also, it makes a summary of development status of AWG. According to the research results above, the hardware and software design plan of the DDS AWG man-machine control system are set up。The system design and implementation process can be divided into the following steps:1,In this paper, the ARM embedded system based on PXA255 is selected to realize DDS. Intel XScale PXA255 is a high-powerful embedded ARM processor introduced by Intel Corporation. It supports virtual memory management with MMU, pipelining, cache and the highest working frequency can be up to 400MHz; LCD do the terminals'display; Touch Screen Module uses AD7843; Terminal uses 32M bytes of FLASH and 64M bytes of SDRAM to store date and operate procedures, and the type are E28F128J3A and K4S281632C.2,U-Boot 1.1.4 is ported as boot loader adapting to this terminal platform. In debug phase, boot loader should support the serial and network in order to debug expediently and download image. Linux 2.4.14 is also ported to this terminal platform. According to hardware interface and time sequencing, the drivers of peripheral equipment based on actual hardware circuit is designed and the management for peripheral interface is realized. A file system with JFFS2 format is realized by using the Busybox.3,This embedded system adopts Linux 2.4.14 as the EOS (Embedded Operation System). Linux is organized with layer structure and opens its source code. Its network is power. And it supports many kinds of file system and can operate on many kinds of embedded processor, including PXA255 processor. This system decides to use host/target cross-platform development mode. In this mode, the host takes charge of building cross-platform development environment and complete most of the development work. At last, the binary code is downloaded to the target platform and run.4,After the building of the software platform, I begin to program the driver and application for the digital storage oscillograph system. The study of driver is using the driver program to visit the hardware registers, and providing the standard interface for the user's program. The study of application is based on the MiniGUI, and the next step is porting MiniGUI as the GUI of this terminal platform.This paper finished design of schematic hardware circuits, design of man-machine operating windows, and software development of ARM control system of AWG, which provided a feasible realization for man-machine system of DDS AWG. For hardware, system used a high-end 32-bit embedded microprocessor as the main controller, and used TFT color LCD, whose resolution was 640×480, to display man-machine operating windows. For software, paper built up a man-machine control system for AWG. It was easy to operate, and was equipped with elaborate illumination. It could use Chinese and English languages also.Through debugging and testing, the hardware and embedded Linux operating system run stably, the GUI is friendly, the system carries out a good result of AWG and ultimately reaches the design request.Finally, the main research contents of full text are summarized, main research conclusions and innovation points are given, and the insufficiency of this paper and research emphases in the future are pointed out... |
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