Research On High Speed Data Acquisition Technology Based On ARMLinux

In this dissertation, a high speed data acquisition technology is researched based on ARMLinux operating system. The system design accomplished includes two parts: software and hardware. The software has been developped with ARMLinux. And the hardware has been constructed on the architecture of ARM & FPGA. The whole system has been tested and the data obtained has been analysed. Meanwhile, we utilized a tool to compare the power dissipation between our system and another similar system established on the architecture of NIOS II, and the result effectively proves that our architecture is better than the latter.The system is described in two parts. One is the hardware design of high speed data acquisition based on the ARM processor and FPGA chip, the other is the program design using the OS (operating system) of ARMLinux.In the hardware design, we chose a chip of AD9481 made by the AD Company, which is able to convert the analog signals to digital signals at the maximum frequency of 250 MHz. And we realized a multiple FIFO and a double-port RAM based on the principle of ping pong in the FPGA chip. We made the system capable of acquiring the target signals by the threshold control, and then triggering the external FIQ (fast interrupt acquisition) of ARM so that the service routine of FIQ can get the data we want through the GPIO (general parallel I/O) of ARM at high speed.In the software design, at firstly we ported the OS of ARMLinux onto ARM for more effective administration and system upgrade. On the software platform, we designed the character device driver of LCD and the application program of data acquisition. By modifying the kernel of ARMLinux, we made ARM capable of getting the high speed data from its external device FPGA by the FIQ. Then a user process can get the data from the system space and display it on the LCD.We realized the system function by utilizing the FIQ of ARM to control external device to acquire the high speed data. In the experiment, the system can normally sample, transfer and display the data at the sampling frequency 125 MHz.