[microprocessor] VHDL development of microprocessor based on FPGA

1. Software version

vivado2019.2

2. Description of algorithm

      Microprocessors are compared with combinational logic controllers , With regularity 、 flexibility 、 Maintainability and other advantages , Therefore, it gradually replaces the early combined logic controller in computer design , And has been widely used ． In computer system , Microprogramming technology is a technology that uses software methods to design hardware .

      Basic idea of microprogramming control , Is to imitate the usual problem-solving procedures , The operation control signals are programmed into so-called “ Microinstructions ”, Stored in a read-only memory ． When the machine is running , Read these microinstructions one after another , So as to generate various operation control signals required by the whole machine , Make the corresponding parts perform the specified operation , The controller using microprogram control mode is called microprocessor . The so-called microprogram control mode refers to that the micro command is not generated by the combinational logic circuit , It is generated by microinstruction decoding . A machine instruction is often executed in several steps , Write several bit commands required for each operation in a single microinstruction in the form of code , Several microinstructions form a microprogram , Corresponding to one and its instructions . In the design CPU when , According to the needs of the instruction system , Prepare the microprograms in advance , And store them in a special memory （ Called control memory ） in . The microprocessor consists of instruction registers IR、 Program counter PC、 Program status word register PSW、 Sequential systems 、 Control memory CM、 Microinstruction register and microaddress forming circuit . Micro address register and other components . When the command is executed , Find the corresponding microprogram segment from the control memory , Fetch microinstructions one by one , Into the microinstruction register , Generate the required micro command after decoding , Control the completion of each step .

· The advantages of microprogramming