|
OPL-3
The OPL (FM Operator Type-L) series are a family of sound chips developed by Yamaha. The OPL series are low-cost sound chips providing FM synthesis for use in computing, music and video game applications. Internal operation The internal operation of the chips is completely digital. Each FM-tone is generated by a digital oscillator using a form of direct digital synthesis. A low-frequency oscillator and an envelope generator drive an FM operator to produce floating-point output for the DAC. Decapsulation of the chips shows two look-up tables, one for calculating exponents and one for log-sine. This allows the FM operator to calculate its output without any multipliers, using the formula \exp log \sin[\varphi_2 + \exp [\log \sin [\varphi_1+ A_1">varphi_2_+_\exp_[\log_\sin_[\varphi_1.html" ;"title="log \sin[\varphi_2 + \exp [\log \sin [\varphi_1">log \sin[\varphi_2 + \exp [\log \sin [\varphi_1+ A_1 + A_2] and two 256-entry look-up tables. Both tables are stored as pairs of values r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sound Chip
A sound chip is an integrated circuit (chip) designed to produce audio signals through digital, analog or mixed-mode electronics. Sound chips are typically fabricated on metal–oxide–semiconductor (MOS) mixed-signal chips that process audio signals (analog and digital signals, for both analog and digital data). They normally contain audio components such as oscillators, envelope controllers, samplers, filters, amplifiers, and envelope generators. History A number of sound synthesis methods for electronically producing sound were devised during the late 20th century. These include programmable sound generators (PSG), wavetable synthesis, and frequency modulation synthesis (FM synthesis). Such sound chips were widely used in arcade game system boards, video game consoles, home computers and digital synthesizers. Since the late-1990s, pulse-code modulation (PCM) sampling has been the standard for many sound chips, as used in the Intel High Definition Audio (IHDA ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phase Modulation
Phase modulation (PM) is a modulation pattern for conditioning communication signals for transmission. It encodes a message signal as variations in the instantaneous phase of a carrier wave. Phase modulation is one of the two principal forms of angle modulation, together with frequency modulation. In phase modulation, the instantaneous amplitude of the baseband signal modifies the phase of the carrier signal keeping its amplitude and frequency constant. The phase of a carrier signal is modulated to follow the changing signal level (amplitude) of the message signal. The peak amplitude and the frequency of the carrier signal are maintained constant, but as the amplitude of the message signal changes, the phase of the carrier changes correspondingly. Phase modulation is widely used for transmitting radio waves and is an integral part of many digital transmission coding schemes that underlie a wide range of technologies like Wi-Fi, GSM and satellite television. It is also used fo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Latency (engineering)
Latency, from a general point of view, is a time delay between the cause and the effect of some physical change in the system being observed. Lag, as it is known in gaming circles, refers to the latency between the input to a simulation and the visual or auditory response, often occurring because of network delay in online games. Latency is physically a consequence of the limited velocity at which any physical interaction can propagate. The magnitude of this velocity is always less than or equal to the speed of light. Therefore, every physical system with any physical separation (distance) between cause and effect will experience some sort of latency, regardless of the nature of the stimulation at which it has been exposed to. The precise definition of latency depends on the system being observed or the nature of the simulation. In communications, the lower limit of latency is determined by the medium being used to transfer information. In reliable two-way communication syst ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Die (integrated Circuit)
A die, in the context of integrated circuits, is a small block of semiconducting material on which a given functional circuit is fabricated. Typically, integrated circuits are produced in large batches on a single wafer of electronic-grade silicon (EGS) or other semiconductor (such as GaAs) through processes such as photolithography. The wafer is cut (diced) into many pieces, each containing one copy of the circuit. Each of these pieces is called a die. There are three commonly used plural forms: ''dice'', ''dies'' and ''die''. To simplify handling and integration onto a printed circuit board, most dies are packaged in various forms. Manufacturing process Most dies are composed of silicon and used for integrated circuits. The process begins with the production of monocrystalline silicon ingots. These ingots are then sliced into disks with a diameter of up to 300 mm. [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Decapping
Decapping (decapsulation) or delidding of an integrated circuit is the process of removing the protective cover or integrated heat spreader (IHS) of an integrated circuit so that the contained die is revealed for visual inspection of the micro circuitry imprinted on the die. This process is typically done in order to debug a manufacturing problem with the chip, or possibly to copy information from the device, to check for counterfeit chips or to reverse engineer it. Companies such as TechInsights and ChipRebel decap, take die shots of, and reverse engineer chips for customers. Modern integrated circuits can be encapsulated in plastic, ceramic, or epoxy packages. Delidding may also be done in an effort to reduce the operating temperatures of an integrated circuit such as a processor, by replacing the thermal interface material (TIM) between the die and the IHS with a higher-quality TIM. With care, it's possible to decap a device and still leave it functional. Method Decapping is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Yamaha YM2413
The YM2413, a.k.a. OPLL, is a cost-reduced Frequency modulation synthesis, FM synthesis sound chip manufactured by Yamaha Corporation and based on their Yamaha YM3812, YM3812 (OPL2). To make the chip cheaper to manufacture, many of the internal registers were removed. The result of this is that the YM2413 can only play one user-defined instrument at a time; the other 15 instrument settings are hard-coded and cannot be altered by the user. There were also some other cost reduction, cost-cutting modifications: the number of waveforms was reduced to two, additive mode was removed along with the 6-bit carrier volume control (channels instead have 15 levels of volume), and the channels are not mixed using an Adder (electronics), adder; instead, the chip's built-in Digital-to-analog converter, DAC uses time-division multiplexing to play short segments of each channel in sequence, which was also done in the YM2612 much later. Applications The YM2413 was used in: * the FM Sound Unit add- ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sinewave Synthesis
Sinewave synthesis, or sine wave speech, is a technique for synthesizing speech by replacing the formants (main bands of energy) with pure tone whistles. The first sinewave synthesis program (''SWS'') for the automatic creation of stimuli for perceptual experiments was developed by Philip Rubin at Haskins Laboratories in the 1970s. This program was subsequently used by Robert Remez, Philip Rubin, David Pisoni, and other colleagues to show that listeners can perceive Perception () is the organization, identification, and interpretation of sensory information in order to represent and understand the presented information or environment. All perception involves signals that go through the nervous system ... continuous speech without traditional speech cues, i.e., pitch, stress, and intonation. This work paved the way for a view of speech as a dynamic pattern of trajectories through articulatory-acoustic space. Bibliography * Rubin, P.E. Sinewave synthesis. Internal memoran ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vibrato
Vibrato (Italian language, Italian, from past participle of "wikt:vibrare, vibrare", to vibrate) is a musical effect consisting of a regular, pulsating change of pitch (music), pitch. It is used to add expression to vocal and instrumental music. Vibrato is typically characterised in terms of two factors: the amount of pitch variation ("extent of vibrato") and the speed with which the pitch is varied ("rate of vibrato"). In singing it can occur spontaneously through variations in the larynx. The vibrato of a string instrument and wind instrument is an imitation of that vocal function. Vibrato and tremolo The terms vibrato and tremolo are sometimes incorrectly used interchangeably, although (in the classical world) they are properly defined as separate effects with vibrato defined as a periodic variation in the pitch (frequency) of a musical note, and tremolo as a fast repetition of the same note (usually a semiquaver) in order to produce the audible effect of a longer note, es ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
