| With the constant development of electronic technology, a variety of intelligent nuclear equipments become more intelligent, more portable gradually. For the traditional multi-channel pulse amplitude analyzer bulky, and human-computer interaction unfriendly, not convenient for analysing pulse in the scene[5]. High-speed, highly integrated, user-friendly multi-channel pulse amplitude analyzer appeared to fill the shortcomings.With the development of electronic technology, processors based on ARM core has been used more and more widely. compared to single-chip, MCU based on ARM has advantages of high speed, and can meets time requirements of multi-channel pulse analyzer. Power consumption of ARM processor is very low, so the type MCU is suitable for some field occasions that required low consumption. the characteristics of ARM can just meet requirements of portable multi-channel pulse amplitude analyzer. At the same time, the ARM core processor has a wealth of peripheral resources, thus simplifying the peripheral circuits, reducing power consumption and enhancing the reliability of the product. In addition, ARM chips can easily portable with varible operating system, this can help multi-channel pulse amplitude analyzer to manage multi-tasks and parallel processing routines, and even provide a chance to come true hard real-time system. Using embedded linux operating system based on ARM platform enables multi-channel pulse amplitude analyzer's software modules upgrade easily.Miniaturization is a trend of intelligent instruments and multi-channel pulse amplitude analyzer. Intelligent systems require a high degree of automation, operation friendly, good fault tolerance. In addition to the need for intelligent control, system also need for hardware control circuit to achieve the corresponding control logic. combination of two above can meet requirements of a real intelligent instruments. Requirements for small-scale systems that need small size, low power consumption, easy to carry; In addition to need micro-consumption components, also the size of circuit board and fewer components is required. but the miniaturization of the system must be maintained at the same time intelligent, that requirement of intelligence need not to reduce the complexity of the logic and timing control functions. Useing high level integrated ARM chips can be satisfied at the same time meet the requirements of intelligence and small volume. In the system, almost all operations controlled by ARM chips can be achieve all requirments such as threshold settings, automatic spectrum stabilization, as well as multi-channel data acquisition. In saving the number of components and circuit board size at the same time maintains the level of intelligent systems.Linux kernel can be easily modified to support multiple processors and variable architecture. It also be suitable for embedded operating system. Embedded linux can run on deferent platforms, from x86, MIPS, POWERPC to ARM. Currently, CPU of ARM architecture occupied gradually most market of 32-bit embedded microprocessor, ARM processor is used in many fields. such as: industrial controlling, wireless communications, networking, consumer electronics, imaging conduction and so on.Multi-channel pulse amplitude analyzer is a key circuit in nuclear spectrum instrument. so, the design of multi-channel pulse amplitude analyzer based on platform of ARM-Linux is introduced in this paper. The instrument used ARM9 as core. and has multi-functions such as: data acquisition, data process, signals control, data displayed in real time. The paper put emphasis on pre-amplify circuits and driver modules. Because of luxuriant peripheral resource, the instrument based on ARM is simplified compare to traditional multi-channel pulse amplitude analyzer designed with 51 MCU. The system provide a kindly Graphical User Interface based on Qt/Embeded Lib. The overall paper offered a new solution for designing of a instrument platform of intellectual energy spectrum by introducing the software and hardware module of the system.Circuit board designed with 6 layers PCB board structure that has increased reliability, improved the stability of the electromagnetic compatibility. Data acquisition system is a multi-channel pulse amplitude analyzer's core, and data acqusition module of the system used built-in ADC of S3C2410. The ADC can meets the minimum conversion time requirements with the max conversion speed of 500 KSPS. With the merits of SD card , the design used it as external data storage devices. SD card driver packages that has been provided is used in this system for convenience. A 640 * 480 resolutions, 6.4 inchs LCD is used for displaying. Qt / Embedded Lib is adopt for providing a graphical user interface. Data acquistion system is based on a embedded database, SQLite. In order to facilitate data transmission, the system using XML Language to format the data that would be sent. Based on TCP / IP protocol, the socket API under Linux OS is used in programming for sending data to PC.
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