Comparison of 8051 with its other family members

Introduction :

8051 is 8-bit microcontroller with 4 KB program memory and 128 Bytes data memory. Other features include four 8-bit ports, two 16-bit timers and one on-chip serial port. Overview of the 8051 Family : 8051 microcontroller was initially designed by Intel Corporation in 1981. Features of 8051 made it extremely popular in market. Because of it’s popularity and high demand Intel allowed other manufacturers to fabricate and market different variants of 8051 with a condition that all these variants should be code compatible with 8051. This resulted in a lot of variants of 8051 in market, among which 8052 and 8031 are the most popular ones. Therefore, 8052 and 8031 are considered as the family members of 8051.

• 8052 – 8052 is the super set of 8051 as it has all the features of 8051 with an extra timer and an extra RAM of 128 bytes. Therefore, 8052 has a total of 256 bytes of RAM and 3 timers in all. Also all the programs written for 8051 will run on 8052 as 8052 is super set of 8051, but it’s reverse is not true.
• 8031 – 8031 is referred to as ROM-less microcontroller chip because it has 0 K byes of on-chip ROM. For it’s operation, 8031 requires external ROM which aids it in fetch and execute operations. Apart from this, it shares almost all the features of 8051.
• 80C31/80C52: The 80C31 and 80C52 are enhanced versions of the 8031 and 8052, respectively. They have additional features such as an on-chip oscillator, an expanded interrupt structure, and a power-down mode. These microcontrollers are also compatible with the 8051 in terms of pinout and instruction set.
• AT89C51/52: The AT89C51 and AT89C52 are popular derivatives of the 8051 developed by Atmel Corporation. They have additional features such as an on-chip flash memory, an expanded interrupt structure, and a power-down mode. These microcontrollers are also compatible with the 8051 in terms of pinout and instruction set, making it easy to migrate code between them.
• STC89C5x: The STC89C5x series of microcontrollers are based on the 8051 architecture but have additional features such as an on-chip flash memory, an expanded interrupt structure, and a power-down mode. They also have higher clock speeds and more I/O pins than the 8051. However, they are not fully compatible with the 8051 in terms of pinout and instruction set, so code migration between them requires some modifications.
• P89V51RD2: The P89V51RD2 is a derivative of the 8051 developed by NXP Semiconductors. It has additional features such as an on-chip flash memory, an expanded interrupt structure, and a power-down mode. It also has a dual-data pointer and a programmable counter array. Like the STC89C5x, it is not fully compatible with the 8051 in terms of pinout and instruction set.

Comparison of 8051 with its other family members : Following table highlights the main characteristics of distinction between 8051, 8052 and 8031 –

Characteristic	8051	8052	8031
RAM	128 bytes	256 bytes	128 bytes
ROM (on-chip)	4 KB	8 KB	0 KB
Number of Timer	2	3	2
Interrupt Sources	6	8	6
Serial Port	1	1	1
Number of I/O Ports	32	32	32

Uses of Comparison of 8051 with its other family members :

 Here are some specific uses of this comparison:

1. Selecting the appropriate microcontroller: By comparing the features of the 8051 with its derivatives, engineers can choose the most suitable microcontroller for their application. They can evaluate the additional features and capabilities of each family member and determine which one best meets their requirements.
2. Code migration: By understanding the similarities and differences between the 8051 and its family members, engineers can migrate code from one microcontroller to another. This can save time and effort in software development and testing.
3. Upgrading existing systems: If an existing system is based on the 8051, engineers can compare it with the features of the newer family members and determine whether an upgrade is necessary. They can evaluate the additional features and benefits of the newer microcontrollers and decide whether an upgrade would improve the performance or functionality of the system.
4. Learning about microcontroller architecture: By comparing the 8051 with its family members, students and hobbyists can learn about microcontroller architecture and understand the tradeoffs between different features and capabilities. This can help them make informed decisions when selecting a microcontroller for their own projects.
5. Developing new applications: By understanding the additional features and capabilities of the 8051 family members, engineers can develop new applications that require specific features such as an on-chip flash memory, expanded interrupt structure, or power-down mode. This can lead to the development of more advanced and sophisticated embedded systems.

Issues in Comparison of 8051 with its other family members :

There are also some potential issues that should be considered:

1. Compatibility: While many of the family members are compatible with the 8051 in terms of instruction set and pinout, there may still be some differences that could affect code migration. Engineers should carefully evaluate the compatibility of the microcontrollers before attempting to migrate code.
2. Development tools: Different microcontrollers may require different development tools, such as compilers, debuggers, and programmers. Engineers should ensure that the necessary tools are available and compatible with the microcontroller they select.
3. Availability: Some family members may be more readily available than others, depending on the region or market. Engineers should consider the availability of the microcontroller when selecting a suitable option.
4. Cost: The cost of the microcontroller may vary depending on its features and capabilities. Engineers should evaluate the cost-benefit of selecting a particular microcontroller based on the requirements of the application.
5. Training and support: The availability of training and support resources may vary depending on the microcontroller. Engineers should consider the availability and quality of training and support when selecting a microcontroller.
6. Power consumption: While the 8051 family members are generally known for their low power consumption, some microcontrollers may consume more power than others due to their additional features and capabilities. Engineers should evaluate the power consumption of the microcontroller to ensure that it meets the requirements of the application.