Microcontroller Tutorial - Brief Introduction of MCS-51 Microcontroller

MCS51 refers to the general name of a series of single-chip microcomputers produced by the American INTEL company (yes, the famous INTEL). This series of single-chip microcomputers includes many varieties, such as 8031, 8051, 8751, 8032, 8052, 8752, etc. Among them, 8051 is the earliest and most typical product. The other single-chip microcomputers in this series are based on 8051. The functions are added, reduced, and changed. Therefore, people are accustomed to using 8051 to call the MCS51 series of single-chip microcomputers. 8031 ​​was the most popular single-chip microcomputer in my country in the past few years, so the name of 8031 ​​can be seen in many occasions. INTEL has authorized the core technology of MCS51 to many other companies, so many companies are making single-chip microcomputers with 8051 as the core. Of course, the functions have changed more or less to meet different needs. Among them, 89C51 is a very popular single-chip microcomputer in my country in recent years. It is developed and produced by the American ATMEL company. Later we will use 89C51 and 89S51 to complete a series of experiments.
 
MCS-51 series microcontrollers
The MCS-51 series microcontrollers are divided into two series, namely the 51 series and the 52 series.
51 series: basic type, according to the configuration of the on-chip ROM, the corresponding chips are 8031, 8051, 8751,
8951 52 series: enhanced type, according to the configuration of the on-chip ROM, the corresponding chips are 8032, 8052, 8752, 8952
The main hardware features of these two series of microcontrollers are as follows:

On-chip ROM type			ROM size	RAM size	Addressing range	I/O Features		Number of interrupt sources
none	ROM	EPROM				counter	Parallel port
8031	8051	8751	4KB	128B	64KB	2*16	4*8	5
80C31	80C51	87C51	4KB	128B	64KB	2*16	4*8	5
8032	8052	8752	8KB	256B	64KB	3*16	4*8	6
80C32	80C52	87C52	8KB	256B	64KB	3*16	4*8	6

 
From the table above, we can see that there is no ROM in the 8031, 8031, 8032, and 80C32 chips. Corresponding to the table above, we can find that the RAM size of the 51 series microcontroller is 128B, the RAM size of the 52 series is 256B, the counter of the 51 series is two 16-bit counters, and the counter of the 52 series is three 16-bit counters. The 51 series has 5 interrupt sources, and the 52 series has 6 interrupt sources.
 
The difference between 8051 and 80C51:
The 80C51 microcontroller was developed on the basis of the 8051, that is, in the development process of microcontrollers, the 8051 came first, and then the 80C51.
The 8051 microcontroller and the 80C51 microcontroller are exactly the same in appearance, and their instruction systems, pin signals, buses, etc. are completely consistent (fully compatible), which means that the software developed under the 8051 can be fully applied to the 80C51, and vice versa, the software developed under the 89C51 can also be applied to the 8051. These two microcontrollers are completely portable.
Since the appearance and internal structure of these two microcontrollers are the same, what is the main difference between them? The
main difference between the 8051 and 80C51 microcontrollers lies in the chip manufacturing process. The manufacturing process of the 80C51 is improved on the basis of the 8051. The
8051 series microcontrollers use the HMOS process: high speed and high density;
the 80C51 series microcontrollers use the CHMOS process: high speed, high density, low power consumption;
that is to say, the 80C51 microcontroller is a low-power microcontroller.