The central processor unit (CPU) which primarily consists of a control unit (CU) and an arithmetic logical unit (ALU) is the kernel of a microcontroller. Its control unit can be implemented in terms of hardwired control or micro-programmed control. The objective of this paper is twofold: to implement a microcontroller with two forementioned control units, and to verify the portability of the VHDL, i.e. from Xilinix to Altera. The way of using VHDL along with the micro-programmed control can tremendously accelerate the design of a microcontroller.