1,885
edits
Changes
→Common Elements in Modern Computer Design
* A central processing unit (CPU) which reads binary [[Machine Language|machine language]] instructions from memory and executes them. The CPU contains multiple [[Register|registers]]. Instructions are executed according to a [[Clock|clock]] pulse, which synchronizes activity across the system.
* Memory, including random-access memory (RAM), which consists of multiple [[Word|words]] of memory which are individually [[Address|addressable]] -- words can be individually written to or read from each address. Memory is used to store both instructions and data. Memory is generally [[Volatile|volatile]], but some non-volatile memory is usually provided for system startup.
* Some memory is connected to the CPU as well as one or more devices for "memory mapped" input/output -- the CPU as one device, and a peripheral such as a video system or disk controller as the second device. Most modern computers use a [httphttps://infocenteren.armwikipedia.comorg/helpwiki/index.jsp?topic=/com.arm.doc.faqs/ka11516.html Von_Neumann_architecture Von Neuman] architecture, with one memory space for both instructions (software) and data. In some systems, devices may be accessed through a separate address range (designated for I/O ports), which acts like memory-mapped I/O but has a distinct addressing scheme. Devices can get the CPU's attention using an [[Computer_Architecture#Interrupts_and_Exceptions|Interrupt]] scheme. Devices include:
** Storage, which is addressable in sectors or blocks, and is used for [[Volatile|non-volatile]], long-term storage of instructions and data.
** Human interface devices (HID), such as keyboards, pointing devices (mice, touchscreens, trackpads, and so forth), and fingerprint readers. These are typically low-speed devices (e.g., people type at 6 characters per second or less).
However, there is an enormous amount of variation even within this general design.
== Popular Architecture Families ==
Throughout this page and the [[:Category:Computer Architecture|Computer Architecture Category]] on this wiki, several architecture families are mentioned, including:
* x86 - The Intel/AMD architecture which debuted with the Intel 8086 processor (16-bit), gained desktop and server dominance as the 386/486/x86 32-bit architecture, and was extended by AMD to the 64-bit x86_64 architecture. Intel and AMD vigorously compete with x86_64 CPUs, which continue as the preeminent server architecture and most popular desktop architecture.
* ARM - An architecture which started with the Acorn computer company, became the dominant mobile and embedded architecture in its 32-bit incarnations, and was extended to 64-bit in version 8 ([[ARMv8]]) with the [[AArch64]] mode. 64-bit ARM processors are dominant in smartphone applications and starting to be compete in server and high-performance computing systems.
* PowerPC - An architecture which has been used in a wide range of applications, from Apple desktop systems to Sony PlayStation CELL processors, and which is now used primarily in IBM midrange and mainframe systems.
* MIPS - An architecture which was used in Sillicon Graphics workstations but has found its primary audience in network infrastructure such as backbone routers and firewall systems.
As well as some architectures which are no longer current:
* 6502 - An 8-bit architecture which helped spawned the home computing/personal computing era.
* Sparc - A RISC architecture developed by Sun Microsystems which powered the high-end workstation and server market for many years.
== Basic CPU Features ==
