Dma controller that restricts adc from memory without interrupting generation of digital words when cpu accesses memory

Abstract

DMA controller for mixed signal device. A mixed signal integrated circuit with memory control is disclosed. A data conversion circuit is provided that is operable to receive an analog input signal and convert discrete samples thereof at a predetermined sampling rate to a digital representations thereof as a plurality of digital words. A memory stores the digital words generated by the data conversion circuit. A processor is included on the integrated circuit and operable to access the memory to output select ones of the digital words for processing thereof in accordance with a predetermined processing algorithm. A memory access controller controls access to the memory by the data conversion circuit and the processor. The memory access controller is operable to restrict access to the memory by the data conversion circuit without interrupting the generation of digital words therefrom when the processor is accessing the memory, and allowing access to the memory by the data conversion circuitry when the processor is not accessing the memory, such that the data conversion circuit can transfer currently generated digital words and previously generated and non stored digital words for storage in said memory upon gaining access thereto.