(1) Thus we may be able to initiate an instruction fetch from store and increment the program counter in one micro-instruction.

(2) Each micro-instruction is divided into two portions, the control bits and the sequencing bits.

(3) Microinstruction format and the field function.

(4) No decoding is needed to microinstruction.

(5) The Microprogrammed Control Unit (MCU) is mainly used to the ordering and obeys of microinstruction.

(6) Combined with the design of a math coprocessor, the paper dis-cusses how to determine microinstruction format and write microgram code. Multiplication code is presented as an example.