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Dynamic Logic (digital Logic)
In integrated circuit design, dynamic logic (or sometimes clocked logic) is a design methodology in combinatory logic circuits, particularly those implemented in MOS technology. It is distinguished from the so-called static logic by exploiting temporary storage of information in stray and gate capacitances. It was popular in the 1970s and has seen a recent resurgence in the design of high speed digital electronics, particularly computer CPUs. Dynamic logic circuits are usually faster than static counterparts, and require less surface area, but are more difficult to design. Dynamic logic has a higher toggle rate than static logic but the capacitive loads being toggled are smaller so the overall power consumption of dynamic logic may be higher or lower depending on various tradeoffs. When referring to a particular logic family, the dynamic adjective usually suffices to distinguish the design methodology, e.g. ''dynamic CMOS'' or ''dynamic SOI'' design. Dynamic logic is distinguis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Theoretical Computer Science
Theoretical computer science (TCS) is a subset of general computer science and mathematics that focuses on mathematical aspects of computer science such as the theory of computation, lambda calculus, and type theory. It is difficult to circumscribe the theoretical areas precisely. The Association for Computing Machinery, ACM's ACM SIGACT, Special Interest Group on Algorithms and Computation Theory (SIGACT) provides the following description: History While logical inference and mathematical proof had existed previously, in 1931 Kurt Gödel proved with his incompleteness theorem that there are fundamental limitations on what statements could be proved or disproved. Information theory was added to the field with a 1948 mathematical theory of communication by Claude Shannon. In the same decade, Donald Hebb introduced a mathematical model of Hebbian learning, learning in the brain. With mounting biological data supporting this hypothesis with some modification, the fields of n ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Threshold Voltage
The threshold voltage, commonly abbreviated as Vth or VGS(th), of a field-effect transistor (FET) is the minimum gate-to-source voltage (VGS) that is needed to create a conducting path between the source and drain terminals. It is an important scaling factor to maintain power efficiency. When referring to a junction field-effect transistor (JFET), the threshold voltage is often called pinch-off voltage instead. This is somewhat confusing since ''pinch off'' applied to insulated-gate field-effect transistor (IGFET) refers to the channel pinching that leads to current saturation behaviour under high source–drain bias, even though the current is never off. Unlike ''pinch off'', the term ''threshold voltage'' is unambiguous and refers to the same concept in any field-effect transistor. Basic principles In n-channel ''enhancement-mode'' devices, a conductive channel does not exist naturally within the transistor, and a positive gate-to-source voltage is necessary to create one su ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electronic Load
A dummy load is a device used to simulate an electrical load, usually for testing purposes. In radio a dummy antenna is connected to the output of a radio transmitter and electrically simulates an antenna, to allow the transmitter to be adjusted and tested without radiating radio waves. In audio systems, a dummy load is connected to the output of an amplifier to electrically simulate a loudspeaker, allowing the amplifier to be tested without producing sound. Load banks are connected to electrical power supplies to simulate the supply's intended electrical load for testing purposes. Radio In radio this device is also known as a dummy antenna or a radio frequency termination. It is a device, usually a resistor, used in place of an antenna to aid in testing a radio transmitter. It is substituted for the antenna while one adjusts the transmitter, so that no radio waves are radiated so that the transmitter does not interfere with other radio transmitters during the adjustments. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Capacitor
A capacitor is a device that stores electrical energy in an electric field by virtue of accumulating electric charges on two close surfaces insulated from each other. It is a passive electronic component with two terminals. The effect of a capacitor is known as capacitance. While some capacitance exists between any two electrical conductors in proximity in a circuit, a capacitor is a component designed to add capacitance to a circuit. The capacitor was originally known as the condenser, a term still encountered in a few compound names, such as the ''condenser microphone''. The physical form and construction of practical capacitors vary widely and many types of capacitor are in common use. Most capacitors contain at least two electrical conductors often in the form of metallic plates or surfaces separated by a dielectric medium. A conductor may be a foil, thin film, sintered bead of metal, or an electrolyte. The nonconducting dielectric acts to increase the capacitor's c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radiation Hardening
Radiation hardening is the process of making electronic components and circuits resistant to damage or malfunction caused by high levels of ionizing radiation (particle radiation and high-energy electromagnetic radiation), especially for environments in outer space (especially beyond the low Earth orbit), around nuclear reactors and particle accelerators, or during nuclear accidents or nuclear warfare. Most semiconductor electronic components are susceptible to radiation damage, and radiation-hardened (rad-hard) components are based on their non-hardened equivalents, with some design and manufacturing variations that reduce the susceptibility to radiation damage. Due to the extensive development and testing required to produce a radiation-tolerant design of a microelectronic chip, the technology of radiation-hardened chips tends to lag behind the most recent developments. Radiation-hardened products are typically tested to one or more resultant-effects tests, including total i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Static Core
Static core generally refers to a microprocessor (MPU) entirely implemented in static logic. A static core MPU may be halted by stopping the system clock oscillator that is driving it, maintaining its state and resume processing at the point where it was stopped when the clock signal is restarted, as long as power continues to be applied. Static core MPUs are fabricated in the CMOS process and hence consume very little power when the clock is stopped, making them useful in designs in which the MPU remains in standby mode until needed and minimal loading of the power source (often a battery) is desirable during standby. In comparison, typical microprocessor designs, those without a static core, only refresh and present valid outputs on their pins during specific periods of the clock cycle. If the clock is slowed, or stopped, the charge on the pin leaks out of the capacitors over time, quickly moving to the default state and no longer being valid. These designs have to ru ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MOS Technology 6502
The MOS Technology 6502 (typically pronounced "sixty-five-oh-two" or "six-five-oh-two") William Mensch and the moderator both pronounce the 6502 microprocessor as ''"sixty-five-oh-two"''. is an 8-bit microprocessor that was designed by a small team led by Chuck Peddle for MOS Technology. The design team had formerly worked at Motorola on the Motorola 6800 project; the 6502 is essentially a simplified, less expensive and faster version of that design. When it was introduced in 1975, the 6502 was the least expensive microprocessor on the market by a considerable margin. It initially sold for less than one-sixth the cost of competing designs from larger companies, such as the 6800 or Intel 8080. Its introduction caused rapid decreases in pricing across the entire processor market. Along with the Zilog Z80, it sparked a series of projects that resulted in the home computer revolution of the early 1980s. Popular video game consoles and home computers of the 1980s and early 1990s, su ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Low-power Electronics
Low-power electronics are electronics, such as notebook processors, that have been designed to use less electric power than usual, often at some expense. In the case of notebook processors, this expense is processing power; notebook processors usually consume less power than their desktop counterparts, at the expense of lower processing power. History Watches The earliest attempts to reduce the amount of power required by an electronic device were related to the development of the wristwatch. Electronic watches require electricity as a power source, and some mechanical movements and hybrid electromechanical movements also require electricity. Usually, the electricity is provided by a replaceable battery. The first use of electrical power in watches was as a substitute for the mainspring, to remove the need for winding. The first electrically powered watch, the Hamilton Electric 500, was released in 1957 by the Hamilton Watch Company of Lancaster, Pennsylvania. The first quartz ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Instruction Step
An instruction step is a method of executing a computer program one step at a time to determine how it is functioning. This might be to determine if the correct program flow is being followed in the program during the execution or to see if variables are set to their correct values after a single step has completed. Hardware instruction step On earlier computers, a knob on the computer console may have enabled step-by-step execution mode to be selected and execution would then proceed by pressing a "single step" or "single cycle" button. Program status word / Memory or general purpose register read-out could then be accomplished by observing and noting the console lights. Software instruction step On later platforms with multiple users, this method was impractical and so single step execution had to be performed using software techniques. Software techniques * Instrumentation - requiring code to be added during compile or assembly to achieve statement stepping. Code can be added ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Clock Rate
In computing, the clock rate or clock speed typically refers to the frequency at which the clock generator of a processor can generate pulses, which are used to synchronize the operations of its components, and is used as an indicator of the processor's speed. It is measured in the SI unit of frequency hertz (Hz). The clock rate of the first generation of computers was measured in hertz or kilohertz (kHz), the first personal computers (PCs) to arrive throughout the 1970s and 1980s had clock rates measured in megahertz (MHz), and in the 21st century the speed of modern CPUs is commonly advertised in gigahertz (GHz). This metric is most useful when comparing processors within the same family, holding constant other features that may affect performance. Determining factors Binning Manufacturers of modern processors typically charge premium prices for processors that operate at higher clock rates, a practice called binning. For a given CPU, the clock rates are determined at th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tri-state Buffer
In digital electronics, a tri-state or three-state buffer is a type of digital buffer that has three stable states: a high output state, a low output state, and a high-impedance state. In the high-impedance state, the output of the buffer is disconnected from the output bus, allowing other devices to drive the bus without interference from the tri-state buffer. This can be useful in situations where multiple devices are connected to the same bus and need to take turns accessing it. Tri-state buffers are commonly used in bus-based systems, where multiple devices are connected to the same bus and need to share it. For example, in a computer system, multiple devices such as the CPU, memory, and peripherals may be connected to the same data bus. To ensure that only one device can transmit data on the bus at a time, each device is equipped with a tri-state buffer. When a device wants to transmit data, it activates its tri-state buffer, which connects its output to the bus and allows it t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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