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T-RAM
Thyristor RAM (T-RAM) is a type of random-access memory dating from 2009 invented and developed by T-RAM Semiconductor, which departs from the usual designs of memory cells, combining the strengths of the DRAM and SRAM: high density and high speed. This technology, which exploits the electrical property known as negative differential resistance and is called thin capacitively-coupled thyristor, Description of the technology is used to create memory cells capable of very high packing densities. Due to this, the memory is highly scalable, and already has a storage density that is several times higher than found in conventional 6T SRAM. It was expected that the next generation of T-RAM memory will have the same density as DRAM. This technology exploits the electrical property known as negative differential resistor and is characterized by the way in which its memory cells are built, combining DRAM efficiency in terms of space with that of SRAM in terms of speed. Very similar to t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Computer Memory
In computing, memory is a device or system that is used to store information for immediate use in a computer or related computer hardware and digital electronic devices. The term ''memory'' is often synonymous with the term '' primary storage'' or ''main memory''. An archaic synonym for memory is store. Computer memory operates at a high speed compared to storage that is slower but less expensive and higher in capacity. Besides storing opened programs, computer memory serves as disk cache and write buffer to improve both reading and writing performance. Operating systems borrow RAM capacity for caching so long as not needed by running software. If needed, contents of the computer memory can be transferred to storage; a common way of doing this is through a memory management technique called '' virtual memory''. Modern memory is implemented as semiconductor memory, where data is stored within memory cells built from MOS transistors and other components on an integrated circ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thyristor
A thyristor () is a solid-state semiconductor device with four layers of alternating P- and N-type materials used for high-power applications. It acts exclusively as a bistable switch (or a latch), conducting when the gate receives a current trigger, and continuing to conduct until the voltage across the device is reversed biased, or until the voltage is removed (by some other means). There are two designs, differing in what triggers the conducting state. In a three-lead thyristor, a small current on its Gate lead controls the larger current of the Anode to Cathode path. In a two-lead thyristor, conduction begins when the potential difference between the Anode and Cathode themselves is sufficiently large (breakdown voltage). Some sources define silicon-controlled rectifier (SCR) and thyristor as synonymous. Other sources define thyristors as more complex devices that incorporate at least four layers of alternating N-type and P-type substrate. The first thyristor devices were ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Random-access Memory
Random-access memory (RAM; ) is a form of 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, CD-RWs, DVD-RWs and the older magnetic tapes and drum memory), 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. RAM contains multiplexing and demultiplexing circuitry, to connect the data lines to the addressed storage for reading or writing the entry. Usually more than one bit of storage is accessed by the same address, and RAM devices often have multiple data lines and are said to be "8-bit" or "16-bit", etc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Memory Cell (computing)
The memory cell is the fundamental building block of computer memory. The memory cell is an electronic circuit that stores one bit of binary information and it must be set to store a logic 1 (high voltage level) and reset to store a logic 0 (low voltage level). Its value is maintained/stored until it is changed by the set/reset process. The value in the memory cell can be accessed by reading it. Over the history of computing, different memory cell architectures have been used, including core memory and bubble memory. Today, the most common memory cell architecture is MOS memory, which consists of metal–oxide–semiconductor (MOS) memory cells. Modern random-access memory (RAM) uses MOS field-effect transistors (MOSFETs) as flip-flops, along with MOS capacitors for certain types of RAM. The SRAM (static RAM) memory cell is a type of flip-flop circuit, typically implemented using MOSFETs. These require very low power to keep the stored value when not being accessed. A second ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dynamic Random-access Memory
Dynamic random-access memory (dynamic RAM or DRAM) is a type of random-access semiconductor memory that stores each bit of data in a memory cell, usually consisting of a tiny capacitor and a transistor, both typically based on metal-oxide-semiconductor (MOS) technology. While most DRAM memory cell designs use a capacitor and transistor, some only use two transistors. In the designs where a capacitor is used, the capacitor can either be charged or discharged; these two states are taken to represent the two values of a bit, conventionally called 0 and 1. The electric charge on the capacitors gradually leaks away; without intervention the data on the capacitor would soon be lost. To prevent this, DRAM requires an external '' memory refresh'' circuit which periodically rewrites the data in the capacitors, restoring them to their original charge. This refresh process is the defining characteristic of dynamic random-access memory, in contrast to static random-access memory (S ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Static Random-access Memory
Static random-access memory (static RAM or SRAM) is a type of random-access memory (RAM) that uses latching circuitry (flip-flop) to store each bit. SRAM is volatile memory; data is lost when power is removed. The term ''static'' differentiates SRAM from DRAM (''dynamic'' random-access memory) — SRAM will hold its data permanently in the presence of power, while data in DRAM decays in seconds and thus must be periodically refreshed. SRAM is faster than DRAM but it is more expensive in terms of silicon area and cost; it is typically used for the cache and internal registers of a CPU while DRAM is used for a computer's main memory. History Semiconductor bipolar SRAM was invented in 1963 by Robert Norman at Fairchild Semiconductor. MOS SRAM was invented in 1964 by John Schmidt at Fairchild Semiconductor. It was a 64-bit MOS p-channel SRAM. The SRAM was the main driver behind any new CMOS-based technology fabrication process since 1959 when CMOS was invented. In 196 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Negative Differential Resistance
In electronics, negative resistance (NR) is a property of some electrical circuits and devices in which an increase in voltage across the device's terminals results in a decrease in electric current through it. This is in contrast to an ordinary resistor in which an increase of applied voltage causes a proportional increase in current due to Ohm's law, resulting in a positive resistance. While a positive resistance consumes power from current passing through it, a negative resistance produces power. Under certain conditions it can increase the power of an electrical signal, amplifying it. Negative resistance is an uncommon property which occurs in a few nonlinear electronic components. In a nonlinear device, two types of resistance can be defined: 'static' or 'absolute resistance', the ratio of voltage to current v / i, and ''differential resistance'', the ratio of a change in voltage to the resulting change in current \Delta v/\Delta i. The term negative resistance means neg ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
6T SRAM
Static random-access memory (static RAM or SRAM) is a type of random-access memory (RAM) that uses latching circuitry (flip-flop) to store each bit. SRAM is volatile memory; data is lost when power is removed. The term ''static'' differentiates SRAM from DRAM (''dynamic'' random-access memory) — SRAM will hold its data permanently in the presence of power, while data in DRAM decays in seconds and thus must be periodically refreshed. SRAM is faster than DRAM but it is more expensive in terms of silicon area and cost; it is typically used for the cache and internal registers of a CPU while DRAM is used for a computer's main memory. History Semiconductor bipolar SRAM was invented in 1963 by Robert Norman at Fairchild Semiconductor. MOS SRAM was invented in 1964 by John Schmidt at Fairchild Semiconductor. It was a 64-bit MOS p-channel SRAM. The SRAM was the main driver behind any new CMOS-based technology fabrication process since 1959 when CMOS was invented. In 1965, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DRAM
Dynamic random-access memory (dynamic RAM or DRAM) is a type of random-access semiconductor memory that stores each bit of data in a memory cell, usually consisting of a tiny capacitor and a transistor, both typically based on metal-oxide-semiconductor (MOS) technology. While most DRAM memory cell designs use a capacitor and transistor, some only use two transistors. In the designs where a capacitor is used, the capacitor can either be charged or discharged; these two states are taken to represent the two values of a bit, conventionally called 0 and 1. The electric charge on the capacitors gradually leaks away; without intervention the data on the capacitor would soon be lost. To prevent this, DRAM requires an external '' memory refresh'' circuit which periodically rewrites the data in the capacitors, restoring them to their original charge. This refresh process is the defining characteristic of dynamic random-access memory, in contrast to static random-access memory (S ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SDRAM
Synchronous dynamic random-access memory (synchronous dynamic RAM or SDRAM) is any DRAM where the operation of its external pin interface is coordinated by an externally supplied clock signal. DRAM integrated circuits (ICs) produced from the early 1970s to early 1990s used an ''asynchronous'' interface, in which input control signals have a direct effect on internal functions only delayed by the trip across its semiconductor pathways. SDRAM has a ''synchronous'' interface, whereby changes on control inputs are recognised after a rising edge of its clock input. In SDRAM families standardized by JEDEC, the clock signal controls the stepping of an internal finite-state machine that responds to incoming commands. These commands can be pipelined to improve performance, with previously started operations completing while new commands are received. The memory is divided into several equally sized but independent sections called ''banks'', allowing the device to operate on a memory ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Volatile Memory
Volatile memory, in contrast to non-volatile memory, is computer memory that requires power to maintain the stored information; it retains its contents while powered on but when the power is interrupted, the stored data is quickly lost. Volatile memory has several uses including as primary storage. In addition to usually being faster than forms of mass storage such as a hard disk drive, volatility can protect sensitive information, as it becomes unavailable on power-down. Most general-purpose random-access memory (RAM) is volatile. Types There are two kinds of volatile RAM: dynamic and static. Even though both types need continuous electrical current to retain data, there are some important differences between them. Dynamic RAM (DRAM) is very popular due to its cost-effectiveness. DRAM stores each bit of information in a different capacitor within the integrated circuit. DRAM chips need just one single capacitor and one transistor to store each bit of information. This makes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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