# Architecture

In order to run some software you need a real machine and real machines come with a great variety of architecture: a kind of differentiation could be

• load/store architecture: instructions are divided in two categories: memory access and ALU operations between registers.
• register architecture: instructions are not divided and operations like add can be between memory and registers.

In particular, the kind of architecture can influence the way a function is called:

## Assembler

There are two notations: Intel and AT&T.

## ISA

Four principles of IS architecture

• simplicity favors regularity
• smaller is faster
• good design demands compromise
• make the common case fast
• Wikipedia
• RISC-V vs x86 - History and Key Differences Explained video

### Microarchitecture

In electronics engineering and computer engineering, microarchitecture, also called computer organization and sometimes abbreviated as µarch or uarch, is the way a given instruction set architecture (ISA) is implemented in a particular processor. A given ISA may be implemented with different microarchitectures; implementations may vary due to different goals of a given design or due to shifts in technology.

### Computer architecture

Computer architecture is the combination of microarchitecture and instruction set designs.

## RISC

The name stands for Reduced instruction set computing: it's a CPU design.

### SPARC

Scalable Processor ARChitecture. It's an ISA.

### POWERPC

Performance Optimization With Enhanced RISC

### 65(C)02

The MOS Technology 6502 is a little-endian 8-bit microprocessor with a 16 bit address bus