A central processing unit is the prime component of any computer. Its role is to carry out any instructions of a computer program. In this project, students are asked to design a CPU from scratch. The outcome of this project will enable one to build a computer with a CPU that can do simple instructions such as moving data from one register to another and performing simple arithmetics.
With that in mind, this project will help one understand the importance of the CPU in a modern computer. Also, this project helps improve skills with breadboards & wiring. Let's jump into more details.
There are six essential parts to building a CPU, let's go through them briefly
Before all, one needs to be comfortable with lab material & binary logic. Specifically, we look at commonly used parts & logic functions.
The timing signal generator for the computer is a clock with a cycle that repeats. It allows the computer the amount of time needed to perform operations.
In order to efficiently spread data throughout the breadboard, the data can be spread in a bus. The program counter of a computer holds the location of an execution to be executed.
The video above shows the functionality of the CPU. Initially, the PC starts at a 0 and counts up to 15. In order to keep track of the count, the LED in the middle row (2nd row to the left) flashes the count in binary. For example, when all four lights are led, the PC is at 15 (1111 in binary). This CPU allows basic functions such as adding numbers and moving data around.