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EHCI
A USB and Firewire Host Controller Interface (UFHC) is a register-level interface that enables a host controller for USB or IEEE 1394 hardware to communicate with a host controller driver in software. The driver software is typically provided with an operating system of a personal computer, but may also be implemented by application-specific devices such as a microcontroller. On the expansion card or motherboard controller, this involves much custom logic, with digital logic engines in the motherboard's controller chip, plus analog circuitry managing the high-speed differential signals. On the software side, it requires a device driver (called a Host Controller Driver, or HCD). IEEE 1394 Open Host Controller Interface Open Host Controller Interface (OHCI) is an open standard. When applied to an IEEE 1394 (also known as FireWire; i.LINK or Lynx) card, OHCI means that the card supports a standard interface to the PC and can be used by the OHCI IEEE 1394 drivers that come with al ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Advanced Host Controller Interface
The Advanced Host Controller Interface (AHCI) is a technical standard defined by Intel that specifies the register-level interface of Serial ATA (SATA) host controllers in a non-implementation-specific manner in its motherboard chipsets. The specification describes a system memory structure for computer hardware vendors to exchange data between host system memory and attached storage devices. AHCI gives software developers and hardware designers a standard method for detecting, configuring, and programming SATA/AHCI adapters. AHCI is separate from the SATA 3 Gbit/s standard, although it exposes SATA's advanced capabilities (such as hot swapping and native command queuing) such that host systems can utilize them. For modern solid state drives, the interface has been superseded by NVMe. The current version of the specification is 1.3.1. Operating modes Many SATA controllers offer selectable modes of operation: legacy Parallel ATA emulation (more commonly called IDE Mod ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Interface (computer Science)
A communication protocol is a system of rules that allows two or more entities of a communications system to transmit information via any variation of a physical quantity. The protocol defines the rules, syntax, semantics, and synchronization of communication and possible error recovery methods. Protocols may be implemented by hardware, software, or a combination of both. Communicating systems use well-defined formats for exchanging various messages. Each message has an exact meaning intended to elicit a response from a range of possible responses predetermined for that particular situation. The specified behavior is typically independent of how it is to be implemented. Communication protocols have to be agreed upon by the parties involved. To reach an agreement, a protocol may be developed into a technical standard. A programming language describes the same for computations, so there is a close analogy between protocols and programming languages: ''protocols are to communica ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Memory-mapped I/O
Memory-mapped I/O (MMIO) and port-mapped I/O (PMIO) are two complementary methods of performing input/output (I/O) between the central processing unit (CPU) and peripheral devices in a computer (often mediating access via chipset). An alternative approach is using dedicated I/O processors, commonly known as channels on mainframe computers, which execute their own instructions. Memory-mapped I/O uses the same address space to address both main memory and I/O devices. The memory and registers of the I/O devices are mapped to (associated with) address values, so a memory address may refer to either a portion of physical RAM or to memory and registers of the I/O device. Thus, the CPU instructions used to access the memory (e.g. ) can also be used for accessing devices. Each I/O device either monitors the CPU's address bus and responds to any CPU access of an address assigned to that device, connecting the system bus to the desired device's hardware register, or uses a dedi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Low Pin Count
The Low Pin Count (LPC) bus is a computer bus used on IBM-compatible personal computers to connect low-bandwidth devices to the CPU, such as the BIOS ROM (BIOS ROM was moved to the Serial Peripheral Interface (SPI) bus in 2006), "legacy" I/O devices (integrated into Super I/O, Embedded Controller, CPLD, and/or IPMI chip), and Trusted Platform Module (TPM). "Legacy" I/O devices usually include serial and parallel ports, PS/2 keyboard, PS/2 mouse, and floppy disk controller. Most PC motherboards with an LPC bus have either a Platform Controller Hub (PCH) or a southbridge chip, which acts as the host and controls the LPC bus. All other devices connected to the physical wires of the LPC bus are peripherals. Overview The LPC bus was introduced by Intel in 1998 as a software-compatible substitute for the Industry Standard Architecture (ISA) bus. It resembles ISA to software, although physically it is quite different. The ISA bus has a 16-bit data bus and a 24-bit add ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Host Adapter
In computer hardware a host controller, host adapter or host bus adapter (HBA) connects a computer system bus which acts as the host system to other network and storage devices. The terms are primarily used to refer to devices for connecting SCSI, SAS, NVMe, Fibre Channel and SATA devices. Devices for connecting to FireWire, USB and other devices may also be called host controllers or host adapters. Host adapters can be integrated in the motherboard or be on a separate expansion card. The term network interface controller (NIC) is more often used for devices connecting to computer networks, while the term converged network adapter can be applied when protocols such as iSCSI or Fibre Channel over Ethernet allow storage and network functionality over the same physical connection. SCSI A connects a host system and a peripheral SCSI device or storage system. These adapters manage service and task communication between the host and target. Typically a device driver, linked to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
RAID
RAID (; redundant array of inexpensive disks or redundant array of independent disks) is a data storage virtualization technology that combines multiple physical Computer data storage, data storage components into one or more logical units for the purposes of data redundancy, performance improvement, or both. This is in contrast to the previous concept of highly reliable mainframe disk drives known as ''single large expensive disk'' (''SLED''). Data is distributed across the drives in one of several ways, referred to as RAID levels, depending on the required level of redundancy (engineering), redundancy and performance. The different schemes, or data distribution layouts, are named by the word "RAID" followed by a number, for example RAID 0 or RAID 1. Each scheme, or RAID level, provides a different balance among the key goals: reliability engineering, reliability, availability, computer performance, performance, and computer data storage#Capacity, capacity. RAID levels ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wireless USB
Wireless USB is a short-range, high-bandwidth wireless radio communication protocol version of the Universal Serial Bus (USB) created by the Wireless USB Promoter Group. It is unrelated to Wi-Fi and Cypress Wireless USB. It was maintained by the WiMedia Alliance which ceased operations in 2009. Wireless USB is based on the WiMedia Alliance's Ultra-WideBand (UWB) common radio platform, which is capable of sending 480 Mbit/s at distances up to and 110 Mbit/s at distances up to . It is designed to operate in the 3.1 to 10.6 GHz frequency range, although local regulatory policies may restrict the legal operating range in some countries. The standard is now obsolete, and no new hardware has been produced for many years, although it has been adopted by Android for precise signaling Support for the standard was deprecated in Linux 5.4 and removed in Linux 5.7 Overview The rationale for this specification was the overwhelming success of USB as a base for peripheral ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Non-Volatile Memory Host Controller Interface
NVM Express (NVMe) or Non-Volatile Memory Host Controller Interface Specification (NVMHCIS) is an open, logical-device interface specification for accessing a computer's non-volatile storage media usually attached via the PCI Express bus. The initial ''NVM'' stands for ''non-volatile memory'', which is often NAND flash memory that comes in several physical form factors, including solid-state drives (SSDs), PCIe add-in cards, and M.2 cards, the successor to mSATA cards. NVM Express, as a logical-device interface, has been designed to capitalize on the low latency and internal parallelism of solid-state storage devices. Architecturally, the logic for NVMe is physically stored within and executed by the NVMe controller chip that is physically co-located with the storage media, usually an SSD. Version changes for NVMe, e.g., 1.3 to 1.4, are incorporated within the storage media, and do not affect PCIe-compatible components such as motherboards and CPUs. By its design, NVM Express a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Conformance Testing
Conformance testing and also known as compliance testing or type testing, is testing or other activities that determine whether a process, product, or service complies with the requirements of a specification, technical standard, contract, or regulation. It is an element of the more general conformity assessment. Testing is often either logical testing or physical testing. The test procedures may involve other criteria from mathematical testing or chemical testing. Beyond simple conformance, other requirements for efficiency, interoperability, or compliance may apply. Conformance testing may be undertaken by the producer of the product or service being assessed, by a user, or by an accredited independent organization, which can sometimes be the author of the standard being used. When testing is accompanied by certification, the products or services may then be advertised as being certified in compliance with the referred technical standard. Manufacturers and suppliers of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
USB Implementers Forum
USB Implementers Forum, Inc. (USB-IF) is a nonprofit organization created to promote and maintain USB (Universal Serial Bus), a set of specifications and transmission procedures for a type of cable connection that has since become used widely for electronic equipment. Its main activities are currently the promotion and marketing of USB, Wireless USB, USB On-The-Go, and the maintenance of standards and specifications for the related devices, as well as a compliance program. The USB-IF was initiated in 1995 by the group of companies that was developing USB, which was made available first during 1996. The founding companies of USB-IF were Compaq, Digital Equipment Corporation, IBM, Intel, Microsoft, NEC and Nortel. Notable current members include HP, NEC, Microsoft, Apple Inc., Intel, and Agere Systems. The working committees within USB-IF are: * Device Working Group * Compliance Committee * Marketing Committee The USB-IF web caters to developers who may register freely f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cost
Cost is the value of money that has been used up to produce something or deliver a service, and hence is not available for use anymore. In business, the cost may be one of acquisition, in which case the amount of money expended to acquire it is counted as cost. In this case, money is the input that is gone in order to acquire the thing. This acquisition cost may be the sum of the cost of production as incurred by the original producer, and further costs of transaction as incurred by the acquirer over and above the price paid to the producer. Usually, the price also includes a mark-up for profit over the cost of production. More generalized in the field of economics Economics () is a behavioral science that studies the Production (economics), production, distribution (economics), distribution, and Consumption (economics), consumption of goods and services. Economics focuses on the behaviour and interac ..., cost is a metric that is totaling up as a result of a process ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
