In the study of microcontrollers, assembly language has always been a love-hate relationship. Those who love it see it as the key to understanding the essence of hardware, while those who hate it find it obscure and inefficient for development.C language’s popularity and advancements in compiler technology have led to a gradual decrease in the number of assembly language users, but will it really disappear completely?
Current Situation: The Number of Assembly Users is Indeed Decreasing
Currently, over 90% of microcontroller development code is written in C language, which offers a more human-like expression and higher development efficiency, along with strong portability. In contrast, assembly language requires direct manipulation of registers and memorization of machine codes. Assembly code is dependent on specific instruction sets, and code from different architectures cannot be generalized. If one only learns 51 assembly, switching to ARM would almost require starting from scratch. Moreover, maintenance is difficult; in large projects, assembly code is hard to modularize and collaborate on, and during debugging, even the developers themselves can easily get lost in a maze.
However, assembly language is not going to disappear for four reasons:
Advantages of Assembly:
1. Irreplaceable Low-Level Control
The reason assembly is hard to eliminate is that it directly manipulates hardware and has high execution efficiency. Assembly instructions correspond one-to-one with machine codes, resulting in small program sizes and fast execution speeds. It allows for direct observation of register and memory states, making hardware problem diagnosis more intuitive.
When resources are limited, in microcontrollers with extremely limited ROM and RAM resources, such as some 8-bit MCUs, assembly can maximize space savings and avoid the redundant code generated by C language compilation.
2. The Last Line of Defense for Low-Level Control
When a system experiences a serious failure, such as a runaway program, assembly is the only language that can directly control the CPU and registers. Just like a surgeon needs the most basic scalpel, assembly is the surgical tool of the electronic world.
3. Extreme Optimization Needs
In fields like aerospace and military, where code execution time requirements are strict to the nanosecond level, manually optimizing critical code with assembly is still a necessary approach. For example, in rocket ignition timing control, missing a single instruction could lead to an accident.
4. The Key to Understanding the Essence of Computers
Assembly helps you see the machine actions behind each line of C code. Understanding how MOV A,#0x01 is executed on hardware aids in grasping core concepts like pointers, interrupts, and stacks.
II. No Need to Master, but Understand the Basics
1. You can aim to master: register operations, addressing modes, and basic instruction sets. Just like learning to drive doesn’t require knowing how to build an engine, you should understand the meanings of the dashboard indicators.
2. Learn through practice: try using assembly to light up an LED, then implement the same functionality in C language. Comparing the compilation results of both will give you an enlightening understanding of how machines work.
3. Treat assembly as a backup: use C language for daily development, but if you encounter critical performance bottlenecks or strange bugs, checking the disassembled code often helps quickly locate the problem.
Assembly is like traditional woodworking; while mechanization has replaced it in everyday furniture production, the skills of a master craftsman remain irreplaceable when restoring artifacts or creating high-end crafts. The development of open-source instruction sets like RISC-V may even allow assembly to rejuvenate in new forms.
Worrying about assembly being eliminated is like worrying that a brush will be replaced by a fountain pen. Writing tools have advanced, but the art of calligraphy endures. For microcontroller developers, understanding assembly is not essential for survival, but it can give you an extra card to play in critical moments. It cultivates not just code workers, but true engineers who understand machines.