FPGA IMPLEMENTATION OF A FUNCTIONAL MICROCONTROLLER

Abstract

In any control and controller system applications, microcontroller is an important module, which provides the control, timing and status signals. A microprocessor is usually defined as “a single chip that contains control logic and data processing logic, so that it can execute instructions listed in a program to operate on some data”. Microcontrollers are nothing but microprocessors with onchip memory. This paper primarily deals with the implementation of an 8 bit microcontroller to perform arithmetic and logical operations. The modules are programmed using Very High Speed IC Hardware Description Language (VHDL). Using top-down approach, the elements of the microcontroller are identified as basic registers, instruction register, program counter, ALU, ROM, Control and timing Unit. All these modules are connected together to form a top module which is controlled by a Finite State Machine (FSM). The Finite State Machine enters each of the predefined states based on the inputs. FSM implementation also aids in changing the functionalities of the system without completely redesigning the system. Finally, in the top level module, these blocks are connected to form a functional microcontroller. In this paper, we have simulated and synthesized the various parameters of microcontroller by using VHDL on Xilinx ISE 8.2i and SPARTAN 3 FPGA board.