Data acquisition with direct memory access

This paper is concerned about using Direct Memory Access (DMA) transfer for real-time data acquisitions from a plug-in data acquisition board Aquarius DSP-1. Since the conversion speed of the modern Analog to Digital Converters is increase-vealy, the using of the interrupts for reading of the conversion results becomes impossible. For the data acquisition system, presented in this paper, this speed is up to 100 kS/s. This problem can be successfully solved using DMA technique. We subsequently describe the hardware of the data acquisition board, which has been used to acquire data. Next, have been presented the functions, in C programming language, for programming a data acquisition via DMA. Finally, we present some results obtained using this kind of data acquisitions, and some conclusions. Keywords and Phrases: real-time data acquisition systems, driver software development and DMA transfer mode.