Direct memory access methods applied to chaotic behavior experiments

This paper deals with the implementation of a PC-controlled benchmark specially suited to real-time experimental investigation of oscillators driven by impulsive parametric pulses. The benchmark performs both the acquisition of the output signal and the generation of the parametric pulses. It also allows the introduction of a programmable delay to investigate its influence on the dynamics of the oscillator. The time required for the building of each pulse has been reduced from 10 ms (typical setting time of a standard programmable generator) to 15 /spl mu/s, employing the standard PC's direct memory access (DMA) transfer and pulse generation capabilities, allowing the investigation of oscillators with relevant frequency content up to 30 kHz.