Chapter 1
Introduction to Microcontrollers and Display Systems
The basic building blocks of any digital computer are the central processing unit (CPU), the memory and the input-output (I/O). The CPU is like the human brain, as it controls all internal operations of the computer. Instructions are fetched from the memory under the control of the CPU, which it then decodes and controls various internal parts of the computer so that the required operations are performed. The CPU also includes an arithmetic and logic unit (ALU), which is used to perform mathematical and logical operations. The result of an operation is stored either in the memory, in a temporary register, or is sent to an I/O port. Two types of memories are used in a computer, as far as memory functionality is concerned. The program memory stores the user instructions and this memory is normally non-volatile, that is the data is not lost after removal of the power. The second type of memory is the data memory, which stores the temporary user data, such as the result of an operation. The I/O ports allow the computer to communicate with the external world. For example, a keyboard is an input device, enabling the user to enter data to the computer. Similarly, a printer is an output device, enabling the user to print out a hard copy of data in paper form. Depending on the actual application and the requirements, a computer may include additional components, such as timers, counters, interrupt logic, clock logic, and so ...
