Abstract: new Direct Memory Access(DMA)based on microprogramming,Microprogram-ming-Controlled Direct Memory Access(MCDMA)is presented,and the constructional mecha-nism of a universal microcomputer data system depending on MCDMA and tight-coupling structure of bulk memory is proposed.In the end,the wide application of this system in the field of test,measurement,control and microcomputer data network is approached.

Key words: memory-accesscontrol, microprogramming, microcomputers-data systems, measure-ment