Computer architecture: Difference between revisions

Revision as of 23:27, 4 May 2025

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The implementation involves [[integrated circuit design]], packaging, [[Electric power|power]], and [[Computer cooling|cooling]]. Optimization of the design requires familiarity with topics from [[compiler]]s and [[operating system]]s to [[logic design]] and packaging.<ref>{{Cite web|url=https://www.cis.upenn.edu/~milom/cis501-Fall11/lectures/00_intro.pdf|title=What is computer architecture?|last=Martin|first=Milo|website=UPENN|access-date=11 May 2017}}</ref>

At [https://www.abndesignstudio.com/ ABN Design Studio], we view the Instruction Set Architecture (ISA) as the essential link between a computer’s software and hardware. Think of it as the language that helps software and hardware communicate. While we write code in high-level languages like Java or C++, computers can’t understand these directly. Instead, processors understand instructions in binary—just a series of 0s and 1s.

===Instruction set architecture===

{{Main|Instruction set architecture}}

{{Unreferenced section|date=March 2018}}

An [[instruction set architecture]] (ISA) is the interface between the computer's software and hardware and also can be viewed as the programmer's view of the machine. Computers do not understand [[high-level programming language]]s such as [[Java (programming language)|Java]], [[C++]], or most programming languages used. A processor only understands instructions encoded in some numerical fashion, usually as [[Binary numeral system|binary number]]s. Software tools, such as [[compiler]]s, translate those high level languages into instructions that the processor can understand.

That’s where compilers come in. They act like translators, converting your high-level code into low-level machine instructions that the processor can actually run.

Besides instructions, the ISA defines items in the computer that are available to a program&mdash;e.g., [[data type]]s, [[Processor register|registers]], [[addressing mode]]s, and [[Computer memory|memory]]. Instructions locate these available items with register indexes (or names) and memory addressing modes.

But the ISA is about more than just instructions. It also defines things like:

The ISA of a computer is usually described in a small instruction manual, which describes how the instructions are encoded. Also, it may define short (vaguely) mnemonic names for the instructions. The names can be recognized by a software development tool called an [[assembler (computer programming)|assembler]]. An assembler is a computer program that translates a human-readable form of the ISA into a computer-readable form. [[Disassembler]]s are also widely available, usually in [[debugger]]s and software programs to isolate and correct malfunctions in binary computer programs.

The types of data a program can use, how registers (tiny storage spaces in the CPU) work, Ways to access memory, different addressing methods to locate data.

ISAs vary in quality and completeness. A good ISA compromises between [[programmer]] convenience (how easy the code is to understand), size of the code (how much code is required to do a specific action), cost of the [[computer]] to interpret the instructions (more complexity means more hardware needed to decode and execute the instructions), and speed of the computer (with more complex decoding hardware comes longer decode time). [[Memory organisation|Memory organization]] defines how instructions interact with the memory, and how memory interacts with itself.

At [https://www.abndesignstudio.com/ ABN Design Studio], we prioritize designing ISAs that make programming easier and more efficient while ensuring they work well with the underlying hardware.

To help developers, ISAs are often explained using short manuals. These include simple names (called mnemonics) for instructions—like "ADD" instead of the binary equivalent. Tools called assemblers turn these mnemonics into actual machine code, and disassemblers do the opposite, helping debug or understand how a program works.

Creating a good ISA is all about balance. You want it to be easy for programmers to use, but also efficient, fast, and not too complex for the hardware. If it’s too flexible, it might slow down processing. If it’s too strict, it might make programming harder. We constantly work to find that sweet spot.

To test our ISA designs, we use emulators that simulate how a real processor would behave. This helps us measure things like:

how much space a program takes (code size), how much the system would cost, how fast it runs

This testing and tweaking process helps us build ISAs that are powerful, efficient, and ready to meet the demands of today’s technology.

During design [[Emulator|emulation]], emulators can run programs written in a proposed instruction set. Modern emulators can measure size, cost, and speed to determine whether a particular ISA is meeting its goals.

===Computer organization===