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概述 在高速数据采集系统中,需要把高速模数转换所得的数据立即存入计算机的存贮器中,在微机系统中,通常以中断或查询方式接收外设送来的数据。这些方式本质上仍然是程序处理过程,不可能以小于3～5条指令的执行时间来处理一个字节的接收。因此,必须寻求其它更有效的方式。 为了实现高速数据采集,可能的方法是:(1)设置缓存器,把模数转换后的数据暂存起来,待采集过程完毕后,再送入计算机进行处理。这样,系统就得增加一个缓存器控制部分。(2)用直接存贮存取(DMA)的方法,按字节高速地把转换好的数据写入计算机的内存中。这两种方式均可做到在一条指令周期内处理完一个字节。
Overview In high-speed data acquisition systems, the data obtained from high-speed analog-to-digital conversion needs to be immediately stored in the memory of the computer. In computer systems, the data sent from the peripherals are usually received by interrupt or polling. These methods are essentially procedural procedures and can not handle one byte of reception with less than three to five instructions’ execution time. Therefore, other more effective ways must be sought. In order to achieve high-speed data acquisition, possible methods are: (1) set the buffer, the data after the analog-digital conversion temporarily stored until the acquisition process is completed, and then sent to the computer for processing. In this way, the system has to add a buffer control section. (2) With direct memory access (DMA) method, according to the byte high-speed conversion of the data written to the computer’s memory. Either way can be done within a single instruction cycle a byte.