Programming languages are crucial when comes to embedded systems. Programmers have various languages to pick from these days, their decision relies on their needs such as user-friendliness, readability, scope, and so on. Among all programming languages, Assembly language aka ASM is the most commonly used and vital language utilized by many sectors and engineers. Assembly language is a low-level language that uses instructions defined by the chip manufacturers. This tutorial covers several topics of Assembly language and explores the merits and disadvantages of assembly language.
Levels in programming languages:
Before discussing the benefits and drawbacks of Assembly language, it is necessary to comprehend how microcontrollers and microprocessors are programmed. When a programmer employs a high-level language such as C, C++, or Python, the code is initially translated to assembly language. Without assembly language, there would be no higher-level programming languages. After translating assembly language, machine language will be translated. Machine language is the highest level of programming language that an MCU or MPU is able to comprehend and operate.
It is possible to directly translate Assembly language or ASM into machine language. This translation from Assembly to machine code is performed by assemblers, a specialized program.
The features of the assembly language are mentioned below:
- It can employ mnemonic operation codes rather than numeric ones, and it offers information about any errors in the code.
- This language aids in specifying the symbolic operand, thus the machine address of that operand is not necessary. It is capable of being represented by a symbol.
- The information can be expressed using decimal notation
Below are the most popular assemblers available.
- Microsoft Assembler(MASM)
- Borland Turbo Assemble (TASM)
- The GNU Assembler (GAS)
What makes Assembly language special:
ASM grants programmers access to the real registers of microcontrollers and other target electronics. It was designed to facilitate the programming of microcontrollers and microprocessors. When programming hardware in machine language, you employ an abundance of “0”s and “1”s. Consider the table below to visualize how disorganized machine code might be.
Difference between Assembly and Machine language
Assembly language substitutes the untidy and inconvenient “0” and “1” characters with mnemonic codes, which are alphanumeric commands. Not only is assembly language simple to parse and comprehend, but it also provides a high level of control and access to registers and memory in the target hardware. Typically, assembly language has three sorts of directives.
- Opcode mnemonic – This refers to a single instruction that performs a specific task. Examples are – MOVE, LOAD, STORE, etc
- Data definitions – These are instructions programmers use to declare the type, size, and scope of data. Examples are – BYTE, SBYTE, WORD, etc
- Assembly directives – These instructions target the assembler software rather than the hardware itself. It instructs the assembler software to start, jump, end, and other functions while executing the code. Examples are – START, END, EQU, etc
Things to know if you intend to program a microcontroller using Assembly language:
By now you would have got a good idea about Assembly language. Before programming target hardware using it you need to be aware of the following things.
- Complete set of instructions provided for the application’s hardware.
- Register structure of the device.
- Development environment/toolchain ( assembler, directives, linkers, etc )
- Addressing modes and peripheral features of the target hardware
Advantages of Assembly language:
- It allows complex jobs to run in a simpler way.
- It is memory efficient, as it requires less memory.
- It is faster in speed, as its execution time is less.
- It is mainly hardware-oriented.
- It requires less instruction to get the result.
- It is used for critical jobs.
- It is not required to keep track of memory locations.
- It is a low-level embedded system.
Disadvantages of Assembly language:
- It takes a lot of time and effort to write the code for the same.
- It is very complex and difficult to understand.
- The syntax is difficult to remember.
- It has a lack of portability of programs between different computer architectures.
- It needs more size or memory of the computer to run the long programs written in Assembly Language.