What are the components of the 51 MCU?

Before learning the internal structure of the microcontroller, let's first understand the major components of the computer we are using now:

The five components of a computer:

Memory: used to store programs and data; (also divided into internal memory and external memory, internal memory is like our computer's hard disk, external memory is like our U disk)

Input device: used to input programs and data to a computer (such as the keyboard and scanner of our computer);

Operator: Used to implement arithmetic and logic operations.

Controller: It is the control and control component of the computer, which enables the various parts of the computer to work automatically and coordinately;

Output Device: The output device is used to display or save the results of computer data calculation or processing in the form required by the user (eg our printer).

Note:

1. The external memory, the input device, and the output device are usually collectively referred to as an external device of the computer.

2. The arithmetic unit and the controller are usually referred to together as a central processing unit (CPU).

What are the components of the 51 MCU?

The figure below is the object we want to study and study, 51 single-chip structure diagram. A double horizontal line in the middle is the internal bus of 51 single-chip microcomputer. The other components are connected to the CPU through the internal bus, and the 8051 microcontroller is a bus structure.

Picture 1

Central Processing Unit (CPU):

The CPU of the MCS-51 can handle 8-bit binary numbers or code. The CPU is the main core component of the microcontroller, and the CPU contains components such as an arithmetic unit, a controller, and a number of registers.

Internal data memory (RAM):

The MCS-51 MCU has a total of 256 RAM cells, of which the last 128 cells are occupied by special registers. The only 128 cells that can be used as registers are used to store readable and writable data. Therefore, the so-called internal data memory refers to the first 128 units, referred to as internal RAM. The address range is 00H~FFH (256B). It is a multi-purpose multi-function data memory with data storage, general working registers, stack, bit address and other space.

Internal program memory (ROM):

As mentioned earlier, the MCS-51 has a 4KB/8KB byte ROM (4KB for the 51 series and 8KB for the 51 series) for storing programs, raw data or tables. So called program memory, referred to as internal RAM. The address range is 0000H~FFFFH (64KB).