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Flash Memory Controller
A flash memory controller (or flash controller) manages data stored on flash memory (usually NAND flash) and communicates with a computer or electronic device. Flash memory controllers can be designed for operating in low duty-cycle environments like memory cards, or other similar media for use in PDAs, mobile phones, etc. USB flash drives use flash memory controllers designed to communicate with personal computers through the USB port at a low duty-cycle. Flash controllers can also be designed for higher duty-cycle environments like solid-state drives (SSD) used as data storage for laptop computer systems up to mission-critical enterprise storage arrays. Initial setup After a flash storage device is initially manufactured, the flash controller is first used to format the flash memory. This ensures the device is operating properly, it maps out bad flash memory cells, and it allocates spare cells to be substituted for future failed cells. Some part of the spare cells is also used ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lexar USB Stick 8 GB - Silicon Motion SM3253L-0309
Lexar Media, Inc. is a Chinese brand of flash memory products manufactured by the Chinese company Longsys. The Lexar "JumpDrive" trademark was often used synonymously with the term USB flash drives when the technology was first adopted. History Early years (1996-2006) Lexar was founded as an American manufacturer of digital media products based in San Jose, California. Products manufactured by Lexar include SD cards, CompactFlash cards, USB flash drives, card readers and solid-state drives. Once a division of Cirrus Logic, Lexar leveraged its parent company's experience in building ATA controllers in developing its own flash controllers. Lexar was spun off from Cirrus Logic in 1996. Lexar was created by Petro Estakhri and Mike Assar. In 2005, Lexar was awarded $380 million in a lawsuit against Toshiba who copied Lexar's flash memory technology. Under Micron ownership (2006-2017) Lexar was acquired by Micron Technology in 2006, and subsequently merged with Cruc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
USB Port
Universal Serial Bus (USB) is an industry standard that establishes specifications for cables, connectors and protocols for connection, communication and power supply (interfacing) between computers, peripherals and other computers. A broad variety of USB hardware exists, including 14 different connector types, of which USB-C is the most recent and the only one not currently deprecated. First released in 1996, the USB standards are maintained by the USB Implementers Forum (USB-IF). The four generations of USB are: USB 1.''x'', USB 2.0, USB 3.''x'', and USB4. Overview USB was designed to standardize the connection of peripherals to personal computers, both to communicate with and to supply electric power. It has largely replaced interfaces such as serial ports and parallel ports, and has become commonplace on a wide range of devices. Examples of peripherals that are connected via USB include computer keyboards and mice, video cameras, printers, portable media players, mob ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Garbage Collection (computer Science)
In computer science, garbage collection (GC) is a form of automatic memory management. The ''garbage collector'' attempts to reclaim memory which was allocated by the program, but is no longer referenced; such memory is called '' garbage''. Garbage collection was invented by American computer scientist John McCarthy around 1959 to simplify manual memory management in Lisp. Garbage collection relieves the programmer from doing manual memory management, where the programmer specifies what objects to de-allocate and return to the memory system and when to do so. Other, similar techniques include stack allocation, region inference, and memory ownership, and combinations thereof. Garbage collection may take a significant proportion of a program's total processing time, and affect performance as a result. Resources other than memory, such as network sockets, database handles, windows, file descriptors, and device descriptors, are not typically handled by garbage collection, but ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MRAM
Magnetoresistive random-access memory (MRAM) is a type of non-volatile random-access memory which stores data in magnetic domains. Developed in the mid-1980s, proponents have argued that magnetoresistive RAM will eventually surpass competing technologies to become a dominant or even universal memory. Currently, memory technologies in use such as flash RAM and DRAM have practical advantages that have so far kept MRAM in a niche role in the market. Description Unlike conventional RAM chip technologies, data in MRAM is not stored as electric charge or current flows, but by magnetic storage elements. The elements are formed from two ferromagnetic plates, each of which can hold a magnetization, separated by a thin insulating layer. One of the two plates is a permanent magnet set to a particular polarity; the other plate's magnetization can be changed to match that of an external field to store memory. This configuration is known as a magnetic tunnel junction and is the simplest st ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wear Leveling
Wear leveling (also written as wear levelling) is a technique Wear leveling techniques for flash memory systems. for prolonging the service life of some kinds of erasable computer storage media, such as flash memory, which is used in solid-state drives (SSDs) and USB flash drives, and phase-change memory. There are several wear leveling mechanisms that provide varying levels of longevity enhancement in such memory systems. The term ''preemptive wear leveling'' (PWL) has been used by Western Digital to describe their preservation technique used on hard disk drives (HDDs) designed for storing audio and video data. However, HDDs generally are not wear-leveled devices in the context of this article. Rationale EEPROM and flash memory media have individually erasable segments, each of which can be put through a limited number of erase cycles before becoming unreliable. This is usually around 3,000/5,000 cycles but many flash devices have one block with a specially extended life of 10 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Firmware
In computing, firmware is a specific class of computer software that provides the low-level control for a device's specific hardware. Firmware, such as the BIOS of a personal computer, may contain basic functions of a device, and may provide hardware abstraction services to higher-level software such as operating systems. For less complex devices, firmware may act as the device's complete operating system, performing all control, monitoring and data manipulation functions. Typical examples of devices containing firmware are embedded systems (running embedded software), home and personal-use appliances, computers, and computer peripherals. Firmware is held in non-volatile memory devices such as ROM, EPROM, EEPROM, and flash memory. Updating firmware requires ROM integrated circuits to be physically replaced, or EPROM or flash memory to be reprogrammed through a special procedure. Some firmware memory devices are permanently installed and cannot be changed after manufacture. C ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Storage Array
A disk array is a disk storage system which contains multiple disk drives. It is differentiated from a disk enclosure, in that an array has cache memory and advanced functionality, like RAID, deduplication, encryption and virtualization. Components of a disk array include: * Disk array controllers * Cache in form of both volatile random-access memory and non-volatile flash memory. * Disk enclosures for both magnetic rotational hard disk drives and electronic solid-state drives. * Power supplies Typically a disk array provides increased availability, resiliency, and maintainability by using additional redundant components (controllers, power supplies, fans, etc.), often up to the point where all single points of failure (SPOFs) are eliminated from the design. Additionally, disk array components are often hot-swappable. Traditionally disk arrays were divided into categories: * Network attached storage (NAS) arrays * Storage area network (SAN) arrays: ** Modular SAN arrays ** M ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mission-critical
A mission critical factor of a system is any factor (component, equipment, personnel, process, procedure, software, etc.) that is essential to business operation or to an organization. Failure or disruption of mission critical factors will result in serious impact on business operations or upon an organization, and even can cause social turmoil and catastrophes. Mission critical systems A mission critical system is a system that is essential to the survival of a business or organization. When a mission critical system fails or is interrupted, business operations are significantly impacted. Mission essential equipment and mission critical application are also known as mission critical system. Examples of mission critical systems are: an online banking system, railway/aircraft operating and control systems, electric power systems, and many other computer systems that will adversely affect business and society when they fail. A good example of a mission critical system is a na ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Laptop
A laptop, laptop computer, or notebook computer is a small, portable personal computer (PC) with a screen and alphanumeric keyboard. Laptops typically have a clam shell form factor with the screen mounted on the inside of the upper lid and the keyboard on the inside of the lower lid, although 2-in-1 PCs with a detachable keyboard are often marketed as laptops or as having a "laptop mode". Laptops are folded shut for transportation, and thus are suitable for mobile use. They are so named because they can be practically placed on a person's lap when being used. Today, laptops are used in a variety of settings, such as at work, in education, for playing games, web browsing, for personal multimedia, and for general home computer use. As of 2022, in American English, the terms ''laptop computer'' and ''notebook computer'' are used interchangeably; in other dialects of English, one or the other may be preferred. Although the terms ''notebook computers'' or ''notebooks'' or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Solid-state Drive
A solid-state drive (SSD) is a solid-state storage device that uses integrated circuit assemblies to store data persistently, typically using flash memory, and functioning as secondary storage in the hierarchy of computer storage. It is also sometimes called a semiconductor storage device, a solid-state device or a solid-state disk, even though SSDs lack the physical spinning disks and movable read–write heads used in hard disk drives (HDDs) and floppy disks. SSD also has rich internal parallelism for data processing. In comparison to hard disk drives and similar electromechanical media which use moving parts, SSDs are typically more resistant to physical shock, run silently, and have higher input/output rates and lower latency. SSDs store data in semiconductor cells. cells can contain between 1 and 4 bits of data. SSD storage devices vary in their properties according to the number of bits stored in each cell, with single-bit cells ("Single Level Cells" or "SLC ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Personal Computer
A personal computer (PC) is a multi-purpose microcomputer whose size, capabilities, and price make it feasible for individual use. Personal computers are intended to be operated directly by an end user, rather than by a computer expert or technician. Unlike large, costly minicomputers and mainframes, time-sharing by many people at the same time is not used with personal computers. Primarily in the late 1970s and 1980s, the term home computer was also used. Institutional or corporate computer owners in the 1960s had to write their own programs to do any useful work with the machines. While personal computer users may develop their own applications, usually these systems run commercial software, free-of-charge software ("freeware"), which is most often proprietary, or free and open-source software, which is provided in "ready-to-run", or binary, form. Software for personal computers is typically developed and distributed independently from the hardware or operating system ma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flash Memory
Flash memory is an electronic non-volatile computer memory storage medium that can be electrically erased and reprogrammed. The two main types of flash memory, NOR flash and NAND flash, are named for the NOR and NAND logic gates. Both use the same cell design, consisting of floating gate MOSFETs. They differ at the circuit level depending on whether the state of the bit line or word lines is pulled high or low: in NAND flash, the relationship between the bit line and the word lines resembles a NAND gate; in NOR flash, it resembles a NOR gate. Flash memory, a type of floating-gate memory, was invented at Toshiba in 1980 and is based on EEPROM technology. Toshiba began marketing flash memory in 1987. EPROMs had to be erased completely before they could be rewritten. NAND flash memory, however, may be erased, written, and read in blocks (or pages), which generally are much smaller than the entire device. NOR flash memory allows a single machine word to be written to an era ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
