A memory cell array has a first and a second storage area. The first storage area has a memory elements selected by an address signal. The second storage area has a memory elements selected by a control signal. A control circuit has a fuse element. When the fuse element has been blown, the control circuit inhibits at least one of writing and erasing from being done on the second storage area.

Nonvolatile Semiconductor Memory Device

A transmission system suitable for video where a sender encodes video for transmission to a receiver at an adjustable date rate The data rate may be adjusted using a delay constraint that constrains the expected delay of transmitted packets The expected delay may be measured from a time that a transmitter encodes a packet to a time that a receiver decodes a packet

Wireless video transmission system

Presents a tutorial on phase-locked loops from a control systems perspective. It starts with an introduction of the loop as a feedback control problem, with both the similarities and differences to traditional control problems. Chief among the differences is the necessary inclusion of two nonlinearities in the loop that are not parasitic, but essential to the loop's operation. Analysis methods, both linear and nonlinear are discussed. Then digital loops are discussed, followed by loop components and a cursory look at noise. Finally, the paper ends with a discussion of different applications of PLLs and their relatives.

http://info-coach.fr/atari/hardware/_fd-hard/pll-tut-talk.pdf

Phase-locked loops: a control centric tutorial

A method of adaptively encoding video in response to an estimation of bandwidth over a transmission channel, where bandwidth estimation uses feedback packets from a receiver acknowledging receipt of video packets transmitted during an interval when the transmitted packets are not stored in a buffer of a lower network layer.

Sender-side bandwidth estimation for video transmission with receiver packet buffer

Packet scheduling for video transmission with sender queue control

A method and apparatus utilizing a quartz crystal resonator with an orientation substantially equal to (yxwl) 21.93°/33.93° vibrating simultaneously in two thickness modes to accurately measure temperature and unknown frequencies or to provide a stable frequency signal source. By combining a quartz crystal resonator of the above type with either digital or analog compensation, the frequency-temperature deviation of one of the crystal mode frequencies is used as an internal thermometer and the second crystal mode frequency as a reference frequency signal. The frequency signal for the thermometer function is utilized by the compensation network to correct the measurements made with, or to stabilize, the frequency of the reference frequency signal. Additionally, the analog or digital compensation is accomplished by means of either a curve-fitting routine or an interpolation look-up table routine.

Quartz resonator cut to compensate for static and dynamic thermal transients

A method and apparatus utilizing a quartz crystal resonator with an orientation substantially equal to (yxwl) 21.93°/33.93° vibrating simultaneously in two thickness modes to provide a stable frequency signal source. By combining a quartz crystal resonator of the above type with either digital or analog compensation, the frequency-temperature deviation of one of the crystal mode frequencies is used as an internal thermometer and the second crystal mode frequency as a reference frequency signal. The frequency signal for the thermometer function is utilized by the compensation network to stabilize the frequency of the reference signal. Additionally, the analog or digital compensation is accomplished by means of either a curve-fitting routine or an interpolation look-up table routine.

Oscillator having a quartz resonator cut to compensate for static and dynamic thermal transients

A data decoder for decoding digital data in a high frequency signal in an optical storage device. A carrier signal derived from the high frequency passed through a zonal bandpass filter and a limiter is multiplied by the high frequency signal passed through a high pass filter. The resulting product is filtered and passed through a comparator forming a digital data stream.

Missing pulse detector using synchronous detection

Correction for harmonic disturbances on rotating storage media in a phase-locked loop. The effects of harmonic disturbances in a phase-locked loop are reduced by employing harmonic correction. Harmonic correction may be present in the loop at all times, or may be switched in once the loop has achieved phase lock. Disturbance within the loop bandwidth is corrected using additional integrating pole or a bump (resonant) filter. Disturbance outside the loop bandwidth is corrected using low pass or a notch (anti-resonant) filter. Alternately, a canceling signal may be generated and added as a feedforward signal. A repetitive control scheme uses a filtered version of the residual errors on previous media rotations as a feedforward signal to cancel harmonic effects.

Harmonic correction in phase-locked loops

A phase detector is disclosed that detects the phase of two inputs with precision. A method and apparatus of phase detecting that subtracts out common errors due to temperature variations and supply voltage fluctuations. The phase detector and method preferably utilize digital circuitry such as exclusive OR gates and differential amplifiers to perform the accurate phase detection. The inputs and outputs may be attenuated or filtered to produce the desired results.

Michael C. Fischer

Papers

Quartz resonator cut to compensate for static and dynamic thermal transients

Oscillator having a quartz resonator cut to compensate for static and dynamic thermal transients

Missing pulse detector using synchronous detection

Harmonic correction in phase-locked loops

Phase detector with high precision