1. The executing of the microcode function of the microprogram controller is very crucial to the instructions decoder in the coprocessor.

2. Controled by microprogram, the instruction set of the bit-slice microprocessor can be expanded and reformed to meet a variety of requirements by replacing PROMs.

3. This paper describes its basic principles. The modular microprogramming is introduced with an example of the emulation microprogram that has been run on the VAX-11/780 computer.

4. Computers with control units implemented in this way are called microprogrammed computers.

5. In the paper, a new idea of controlling and managing complicated logic circuits by on chip microprogram is suggested,() since XILINX FPGA is ROM based.

6. By debugging the virtual machine, the test and verification of the organization and microprogram was completed.

7. The design doubles the speed of code by improving the circuit of detecting synchronous signal and changing the work mode of microprogram.

8. A hybrid computer level whose instructions are interpreted by both the operating system and directly by the microprogram.

9. There are two kinds of mode, increment and decision, used for microprogram sequential control.

10. An introduction is given to the implementation of a typical microprogram controller on EDA multipurpose experimental platform.