Programmable function controller for use in a waveform generator system

A programmable function controller for use in a waveform generator system which generates waveforms wherein said controller controls the generation of the waveforms in dependence upon preloaded programmed control words, said system having a plurality of clock sources, a preloaded memory, and digital to analog converter means, and said controller comprises:

• a plurality of data registers for respectively receiving and being preloaded prior to waveform generation with programmed parameter control words respecting the manner in which a waveform is to be generated;
• clock select logic means coupled to one of said registers and responsive to a control word therein for selecting one of said plurality of clock sources including at least two different internal clock sources internal to said system of different frequencies and an external clock source external to said system for providing clock pulses for use by the controller;
• memory address counting means sequentially incremented by said clock pulses for providing sequential addresses for use in sequentially addressing said preloaded memory to obtain therefrom data words sequentially representing data points on a waveform to be generated;
• means for outputting said data words to said digital-to-analog converter means for providing an analog version of said waveform;
• wherein said one of data registers includes a command word register for receiving and being preloaded prior to waveform generation with a control word commanding clock selection of one of said plurality of clock sources, said clock select logic means being coupled to said command word register for responding to said control word therein for selecting a clock source for use by the controller as an internal master clock;
• and,
• a sample time register for receiving and being preloaded prior to waveform generation with a sample time control word defining one of a plurality scaling factors, and sample time counting means responsive to said sample time control word and to said master clock for dividing down said master clock to obtain an addressing clock.