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JEDEC Memory Standards
The JEDEC memory standards are the specifications for semiconductor memory circuits and similar storage devices promulgated by the Joint Electron Device Engineering Council (JEDEC) Solid State Technology Association, a semiconductor trade and engineering standardization organization. JEDEC Standard 100B.01 specifies common terms, units, and other definitions in use in the semiconductor industry. JESC21-C specifies semiconductor memories from the 256 bit static RAM to DDR4 SDRAM modules. JEDEC standardization goals The Joint Electron Device Engineering Council characterizes its standardization efforts as follows: JEDEC Standard 100B.01 The December 2002 JEDEC Standard 100B.01 is entitled ''Terms, Definitions, and Letter Symbols for Microcomputers, Microprocessors, and Memory Integrated Circuits''. The purpose of the standard is to promote the uniform use of symbols, abbreviations, terms, and definitions throughout the semiconductor industry. Units of information T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Joint Electron Device Engineering Council
The Joint Electron Device Engineering Council (JEDEC) Solid State Technology Association is a consortium of the semiconductor industry headquartered in Arlington, United States. It has over 300 members and is focused on standardization of part numbers, defining an electrostatic discharge (ESD) standard, and leadership in the lead-free manufacturing transition. The origin of JEDEC traces back to 1944, when RMA (subsequently renamed EIA) and NEMA established the Joint Electron Tube Engineering Council (JETEC) to coordinate vacuum tube type numberings. In 1958, with the advent of semiconductor technology, the joint JETEC-activity of EIA and NEMA was renamed into Joint Electron Device Engineering Council. NEMA discontinued its involvement in 1979. In the fall of 1999, JEDEC became a separate trade association under the current name, but maintained an EIA alliance, until EIA ceased operations in 2011. History The origin of JEDEC can be traced back to 1944, when the Radio M ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Random Access Memory
Random-access memory (RAM; ) is a form of electronic computer memory that can be read and changed in any order, typically used to store working data and machine code. A random-access memory device allows data items to be read or written in almost the same amount of time irrespective of the physical location of data inside the memory, in contrast with other direct-access data storage media (such as hard disks and magnetic tape), where the time required to read and write data items varies significantly depending on their physical locations on the recording medium, due to mechanical limitations such as media rotation speeds and arm movement. In today's technology, random-access memory takes the form of integrated circuit (IC) chips with MOS (metal–oxide–semiconductor) memory cells. RAM is normally associated with volatile types of memory where stored information is lost if power is removed. The two main types of volatile random-access semiconductor memory are static ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DDR4 SDRAM
Double Data Rate 4 Synchronous Dynamic Random-Access Memory (DDR4 SDRAM) is a type of synchronous dynamic random-access memory with a high bandwidth (" double data rate") interface. Released to the market in 2014, it is a variant of dynamic random-access memory (DRAM), some of which have been in use since the early 1970s, and a higher-speed successor to the DDR2 and DDR3 technologies. DDR4 is not compatible with any earlier type of random-access memory (RAM) due to different signaling voltage and physical interface, besides other factors. DDR4 SDRAM was released to the public market in Q2 2014, focusing on ECC memory, while the non-ECC DDR4 modules became available in Q3 2014, accompanying the launch of Haswell-E processors that require DDR4 memory. Features The primary advantages of DDR4 over its predecessor, DDR3, include higher module density and lower voltage requirements, coupled with higher data rate transfer speeds. The DDR4 standard allows for DIMMs of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Byte
The byte is a unit of digital information that most commonly consists of eight bits. Historically, the byte was the number of bits used to encode a single character of text in a computer and for this reason it is the smallest addressable unit of memory in many computer architectures. To disambiguate arbitrarily sized bytes from the common 8-bit definition, network protocol documents such as the Internet Protocol () refer to an 8-bit byte as an octet. Those bits in an octet are usually counted with numbering from 0 to 7 or 7 to 0 depending on the bit endianness. The size of the byte has historically been hardware-dependent and no definitive standards existed that mandated the size. Sizes from 1 to 48 bits have been used. The six-bit character code was an often-used implementation in early encoding systems, and computers using six-bit and nine-bit bytes were common in the 1960s. These systems often had memory words of 12, 18, 24, 30, 36, 48, or 60 bits, corresponding t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kilo-
Kilo is a decimal prefix, decimal metric prefix, unit prefix in the metric system denoting multiplication by one thousand (103). It is used in the International System of Units, where it has the symbol k, in Letter case, lowercase. The prefix ''kilo'' is derived from the Greek language, Greek word (), meaning "thousand". In 19th century English it was sometimes spelled chilio, in line with a Linguistic purism, puristic opinion by Thomas Young (scientist), Thomas Young. As an opponent of suggestions to introduce the metric system in Britain, he qualified the nomenclature adopted in France as barbarous. Examples * one kilogram (kg) is 1000 grams * one kilometre (km) is 1000 metres * one kilojoule (kJ) is 1000 joules * one kilolitre (kL) is 1000 litres * one kilobaud (kBd) is 1000 bauds * one kilohertz (kHz) is 1000 hertz * one kilodalton (kDa) is 1000 Dalton (unit), daltons * one kilobit (kb) is 1000 bits * one kilobyte (kB) is 1000 bytes * one kiloohm is (kΩ) is 1000 ohms * ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mega-
Mega is a metric prefix, unit prefix in metric systems of units denoting a factor of one million (106 or 1000000 (number), ). It has the unit symbol M. It was confirmed for use in the International System of Units (SI) in 1960. ''Mega'' comes from . Common examples of usage * Megapixel: 1 million pixels in a digital camera * One megatonne of TNT equivalent amounts to approx. 4 petajoules and is the approximate energy released on igniting one million tonnes of TNT. The unit is often used in measuring the explosive power of nuclear weapons. * Megahertz: frequency of electromagnetic radiation for radio and television broadcasting, GSM, etc. 1 MHz = 1,000,000 Hertz, Hz. * Megabyte: unit of information equal to one million bytes (SI standard). * Megawatt: equal to one million watts of power. It is commonly used to measure the output of power plants, as well as the power consumption of electric locomotives, data centers, and other entities that heavily consume electricity. * ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Giga-
Giga- ( or ) is a unit prefix in the metric system denoting a factor of a short-scale billion or long-scale milliard (109 or 1,000,000,000). It has the symbol G. ''Giga-'' is derived from the Greek word (''gígas''), meaning "giant". The ''Oxford English Dictionary'' reports the earliest written use of ''giga'' in this sense to be in the Reports of the IUPAC 14th Conférence Internationale de Chimie in 1947: "The following prefixes to abbreviations for the names of units should be used: G giga 109×." However, it was already used in 1932 by the German organization ''Verband deutscher Elektrotechniker''. When referring to information units in computing, such as gigabyte, giga may sometimes mean (230); this causes ambiguity. Standards organizations discourage this and use giga- to refer to 109 in this context too. ''Gigabit'' is only rarely used with the binary interpretation of the prefix. The binary prefix gibi has been adopted for 230, while reserving ''giga'' exclusive ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Binary Prefixes
A binary prefix is a unit prefix that indicates a multiple of a unit of measurement by an integer power of two. The most commonly used binary prefixes are kibi (symbol Ki, meaning ), mebi (), and gibi (). They are most often used in information technology as multipliers of bit and byte, when expressing the capacity of storage devices or the size of computer files. The binary prefixes "kibi", "mebi", etc. were defined in 1999 by the International Electrotechnical Commission (IEC), in the IEC 60027-2 standard (Amendment 2). They were meant to replace the metric (SI) decimal power prefixes, such as "kilo" (), "mega" () and "giga" (), that were commonly used in the computer industry to indicate the nearest powers of two. For example, a memory module whose capacity was specified by the manufacturer as "2 megabytes" or "2 MB" would hold = , instead of = . On the other hand, a hard disk whose capacity is specified by the manufacturer as "10 gigabytes" or "10&nb ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Serial Communication
In telecommunication and data transmission, serial communication is the process of sending data one bit at a time, sequentially, over a communication channel or computer bus. This is in contrast to parallel communication, where several bits are sent as a whole, on a link with several parallel channels. Serial communication is used for all long-haul communication and most computer networks, where the cost of cable and difficulty of synchronization make parallel communication impractical. Serial computer buses have become more common even at shorter distances, as improved signal integrity and transmission speeds in newer serial technologies have begun to outweigh the parallel bus's advantage of simplicity (no need for serializer and deserializer, or SerDes) and to outstrip its disadvantages (clock skew, interconnect density). The migration from PCI to PCI Express (PCIe) is an example. Modern high speed serial interfaces such as PCIe send data several bits at a time using m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CAS Latency
Column address strobe latency, also called CAS latency or CL, is the delay in clock cycles between the READ command and the moment data is available. In asynchronous DRAM, the interval is specified in nanoseconds (absolute time). In synchronous DRAM, the interval is specified in clock cycles. Because the latency is dependent upon a number of clock ticks instead of absolute time, the actual time for an SDRAM module to respond to a CAS event might vary between uses of the same module if the clock rate differs. RAM operation background Dynamic RAM is arranged in a rectangular array. Each row is selected by a horizontal ''word line''. Sending a logical high signal along a given row enables the MOSFETs present in that row, connecting each storage capacitor to its corresponding vertical ''bit line''. Each bit line is connected to a ''sense amplifier'' that amplifies the small voltage change produced by the storage capacitor. This amplified signal is then output from the DRAM chip ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IEC 60027
IEC 60027 (formerly IEC 27) is a technical standard, technical international standard for letter symbols published by the International Electrotechnical Commission (IEC), comprising the following parts: * IEC 60027-1: General * IEC 60027-2: Telecommunications and electronics * IEC 60027-3: Logarithmic and related quantities, and their units * IEC 60027-4: Symbols for quantities to be used for rotating electrical machines * IEC 60027-6: Control technology * IEC 60027-7: Physiological quantities and units A closely related international standard on physical quantity, quantities and physical unit, units is ISO 31. The ISO 31 and IEC 60027 Standards are being revised by the two standardization organizations in collaboration. The revised harmonized standard is known as ISO/IEC 80000, Quantities and units. It supersedes both ISO 31 and part of IEC 60027. IEC 60027-2 IEC 60027-2 Amendment 2, as published in January 1999, was the first international standard defining the binary prefixes, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IEC 80000-13
ISO/IEC 80000, ''Quantities and units'', is an international standard describing the International System of Quantities (ISQ). It was developed and promulgated jointly by the International Organization for Standardization (ISO) and the International Electrotechnical Commission (IEC). It serves as a style guide for using physical quantities and units of measurement, formulas involving them, and their corresponding units, in scientific and educational documents for worldwide use. The ISO/IEC 80000 family of standards was completed with the publication of the first edition of Part 1 in November 2009. Overview By 2021, ISO/IEC 80000 comprised 13 parts, two of which (parts 6 and 13) were developed by IEC and the remaining 11 were developed by ISO, with a further three parts (15, 16 and, 17) under development. Part 14 was withdrawn. Subject areas By 2021 the 80000 standard had 13 published parts. A description of each part is available online, with the complete parts for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
