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).
