Abstract: An incoming television signal to a television receiver is switched to either NTSC (National Television Systems Committee) processing circuitry (130) or ATV (Advanced Television) processing circuitry (140) as determined from power measurements in each of two separate sub-bands of the power spectrum of the incoming signal. The first power measurement is obtained from a sub-band (204) wherein the NTSC power spectrum has significant spectral energy, whereas the second power measurement is obtained from another sub-band (205) wherein the NTSC power spectrum has minimal spectral energy. If the first measurement exceeds the second measurement by a prescribed value, the television signal is processed by the NTSC circuitry; otherwise, the ATV circuitry effects processing of the incoming signal.

Abstract: A smart mass gas flow sensor is having a housing with a bore through which a gas flows in which a sensor in the housing generates an analog signal proportional to the mass gas flow through the housing bore. A digital processor digitally processes the analog signal from the sensor and generates a substantially linear output signal representative of the mass gas flow through the housing bore.

Abstract: A cold start fuel injector is disclosed for use with an internal combustion engine of the type having an intake manifold and a fuel injection system. The cold start fuel injector includes a housing having a fuel inlet and a fuel outlet. An outlet contained within the housing is fluidly connected to the fuel inlet and, when provided pressurized fuel at its inlet, generates a fuel spray into the intake manifold. A tubular and cylindrical heater is provided around the outlet from the nozzle so that the fuel spray from the nozzle passes through the heater and, in doing so, is vaporized for better fuel combustion and, thus, reduced emissions. Additionally, a mesh is preferably provided within the interior of the heater. This mesh which is optionally heated prevents large droplets of fuel from contacting and unduly cooling the heater. Similarly, fuel at a reduced pressure is provided to the nozzle of the cold start fuel injector.

Abstract: Method for increasing the recording time of a digital video tape recorder ("VTR") and for supporting multiple normal play modes of digital VTR operation, e.g., a standard play mode of operation and one or more long play modes of operation. To achieve long play mode operation data reduction is performed on a received full rate video data stream to generate a reduced rate video data stream. Data reduction is performed using data prioritization and selection, requantization of full rate data stream, and/or by selecting data to be included in the reduced rate data stream as a function of what portion of a video frame the data represents. The reduced rate data stream is generated to be compliant with the data format of the full rate data stream. During long play mode recording operation the data in the reduced rate data stream is recorded on a tape at the same tape data density as used during standard mode VTR operation.

Abstract: A cold start fuel control system as provided for an internal combustion engine of the type having at least one combustion chamber, an intake manifold and a source of fuel. A fuel vapor canister has an interior chamber fluidly connected to the source of fuel and a normally closed shut-off valve fluidly connected between the canister and ambient air. A normally closed purge valve is then fluidly connected in series between the interior of the canister and the intake manifold. The system also includes a cold start fuel injector having an inlet connected to the fuel source and an outlet open to the intake manifold or, optionally, to the interior of the fuel vapor canister. During a cold start engine condition, fuel is supplied as needed from both the fuel vapor canister and cold start injector by activating the cold start injector and simultaneously opening the purge and shut-off valves in synchronism with the engine intake cycle(s).

Abstract: A carrier recovery system for use in illustratively a passband QAM (quadrature amplitude modulation) demodulator (10) and specifically such a system, including apparatus and accompanying methods, that employs separate acquisition and tracking modes and automatic carrier-to-noise estimation. In particular, a carrier recovery system (200) is operated in two modes: an acquisition mode to first attain an initial carrier lock, during which simplified reduced constellation slicing is used to determine a quadrant of each incoming symbol; and a tracking (or lock) mode, during which full slicing is used, to accurately track variations in frequency and phase that may occur to a carrier while the system remains locked. The mode changes based upon whether, e.g., the average error energy associated with fully sliced symbols is greater than or less than a pre-defined switching threshold value.

Abstract: A fuel control system is provided for an internal combustion engine having at least one combustion chamber, an intake air passageway, a multipoint fuel injector associated with each engine combustion chamber and a cold start fuel injector having a fuel outlet open to the intake air passageway. An air valve has an air inlet fluidly connected to the intake air passage and an air outlet fluidly connected to the cold start fuel injector. This air valve movable between an open position and a closed position where in the open position, air flow through the air valve is directed to the cold start fuel injector. During a cold start engine operating condition, air flow through the air valve and cold start fuel injector enhances fuel atomization of the fuel from the cold start fuel injector thereby reducing the desirable engine emissions, and particularly, hydrocarbon engine emissions.

Abstract: A synchronous pulse generator (100) for producing synchronization pulses that are synchronized with a preamble pattern contained in an input digital data signal. The generator contains a correlator circuit (102), a pulse generator circuit (106) and a flywheel circuit (104). The correlator circuit is an M-bit out of N-bit preamble correlator which periodically generates timing pulses whenever M-bits in a received preamble match M-bits in an N-bit preamble pattern. The pulse generator circuit periodically generates a synchronization pulse at a rate equivalent to an expected rate of occurrence of the preambles. The flywheel circuit monitors the occurrence of the timing pulses from the correlator circuit relative to the synchronization pulse occurrences from the pulse generator circuit. Furthermore, the flywheel circuit resets the pulse generator circuit when the timing pulses are not synchronized with the synchronization pulses for a pre-defined period of time.

Abstract: Method for increasing the recording time of a digital video tape recorder ("VTR") and for supporting multiple normal play modes of digital VTR operation, e.g., a standard play mode of operation and one or more long play modes of operation. To achieve long play mode operation data reduction is performed on a received full rate video data stream to generate a reduced rate video data stream. Data reduction is performed using data prioritization and selection, requantization of full rate data stream, and/or by selecting data to be included in the reduced rate data stream as a function of what portion of a video frame the data represents. The reduced rate data stream is generated to be compliant with the data format of the full rate data stream. During long play mode recording operation the data in the reduced rate data stream is recorded on a tape at the same tape data density as used during standard mode VTR operation.

Abstract: A data processor that includes an interrupt controller, a condition code register, a condition code stacking register, a data memory with a stacking area, a data processing unit, and an interrupt request decoder. The interrupt controller receives interrupt request signals including a break interrupt request signal and a plurality of standard interrupt request signals. The condition code register stores condition code values including a data processor mode control value. The data processing unit performs data processing operations. The data processing operations are suspended when the data processor mode control value is set to a predefined "sleep mode" value and are enabled when the data processor mode control value is set to a predefined "run mode".

Abstract: An engine monitoring system and/or emission reduction system is provided for use in conjunction with an internal combustion engine. The system includes a plurality of sensors which detect various engine operating conditions and in which each sensor generates an output signal representative of its particular engine operating condition. At least one of these sensors is a gas sensor associated with the exhaust system which produces an output signal indicative of the concentration of nitric oxides in the exhaust emissions and which has an output which varies as a function of the concentration of such nitric oxides. A central processing unit receives inputs from the various engine sensors and, in accordance with preprogrammed algorithms, monitors the engine for failure and/or deterioration of various components in the emission reduction system as well as the various engine sensors.

Abstract: An arithmetic operation execution unit includes a plurality of 2N bit data registers and an arithmetic logic unit (ALU). The execution unit is coupled to data busses each having a data path width of N bits for transferring data to and from the data registers. An XOR gate and inverter gate are provided for computing a quotient bit QB and a next ALU operation command bit QOP. A bit processing unit (BPU) shifts the QB bit generated during the previous instruction cycle into an output register during each instruction cycle. The execution unit responds to three predefined division instructions by configuring the ALU, BPU and XOR gate to perform three distinct functions. A first instruction performed for each division computation computes initial QB and QOP values. A second instruction is executed multiple times.

Abstract: An air-assist fuel injection system controls the supply of compressed air to the fuel injectors according to the operating status of internal combustion engine. For cold start operation, compressed air is supplied continuously to the injectors; while, for partial load (cruising) and partial acceleration, air is supplied as a pulsating (air volume control) flow consisting of air pulses coincident with the injected fuel pulses. On the other hand, for acceleration and deceleration, the supply of compressed air to the injectors may be inhibited. Further, idle speed control can be achieved using the air-assist to the fuel injectors, thereby eliminating need for a separate idle speed control valve. To enhance system operation, a fuel injector may be employed in which both the fuel and the applied compressed air are swirled, but in opposite directions, so as to achieve a fuel spray of small particle size.

Abstract: A complex NTSC interference canceler for eliminating NTSC signal interference from in-phase and quadrature phase received television signals including both a desired HDTV signal and NTSC interference signal. The complex NTSC interference canceler uses a bank of complex recursive notch filters with adjustable center frequencies to isolate the NTSC signal's major components, i.e. the picture carrier signal, the chrominance subcarrier signal and the audio carrier signal. A single complex filter is used to isolate each NTSC interference signal component, with each particular filter's center frequency being adjusted to match the frequency of the particular NTSC interference signal component to be isolated by the filter. Each filter's gain may be either fixed or dynamically adjusted to match the amplitude of the NTSC interference signal component. Once isolated, the interference signal components are subtracted from the in-phase and quadrature phase received television signals.

Abstract: An implementation efficient digital timing recovery circuit capable of being implemented without the use of multipliers. The circuit includes a voltage controlled crystal oscillator ("VCXO"), a signal generator, a non-linear operation circuit, a digital bandpass filter, a bi-quadratic filter, a digital phase lock loop circuit (DPLL) and a zero crossing detector circuit. The circuit implements a spectral line extraction technique for symbol timing recovery. A signal is received by a tuner, passed through an analog to digital converter, whose sampling rate is controlled by the timing recovery circuit, and is then supplied to a Nyquist filter. The In-phase and quadrature-phase signals output by the Nyquist filter are passed through the non-linear operation circuit to produce a signal which is then passed through the bandpass filter and then the bi-quadratic filter which has a passband centered at the symbol rate of the received signal.

Abstract: A modulo addition circuit generates a sequence of values within a specified range having a lower bound value and an upper bound value. The modulo addition circuit generates a first value by adding a displacement value to a previously defined starting value, and generates a second value by adding to or subtracting from the first generated value a modulo value. Both the first and second values are generated in a single computational cycle using a single address circuit. When the first generated value is in the range defined the lower bound and upper bound values, the modulo addition circuit outputs the first value; otherwise the modulo addition circuit outputs the second generated value. The value output by the modulo addition circuit is stored in a register so as to be available as the starting value in a next computational cycle.

Abstract: A technique for determining the constellation size of a QAM signal received by a QAM receiver. In general, the implementation of my technique has, as an input signal, a QAM signal having one of a plurality of constellation sizes and determines of constellation size, e.g., 4, 16, 32-ary, by analyzing the probability density function (pdf) of the QAM signal over a pre-established time period. To properly analyze the QAM signal, the signal is-first squared and then normalized to a preset value, e.g., 2.0. As such, the signal power in any of the various constellations is normalized to a fixed level. By generating a histogram of the squared and normalized QAM signal, the technique determines the number of levels of modulation contained in the QAM signal. Each constellation size has a unique number of modulation levels and thus forms unique histogram. From the histogram, a particular constellation size can be determined.

Abstract: A video recorder compatible receiver for receiving video data from a video recorder such as a video tape recorder ("VTR"). The receiver includes an error concealment circuit, a digital VTR port adapted for coupling to a VTR and/or a tuner module. The receiver receives digital video data from the VTR by either the digital VTR port or the tuner module. VTR commands may also be received from a VTR. Upon receiving a VTR command indicating that the VTR is operating in trick play mode or upon detecting video data that is indicative of VTR trick play operation, the error concealment circuit of the receiver disables normal play error concealment and enables trick play error concealment. The error concealment circuit may perform temporal and spatial filtering on the video data received from the VTR when trick play error concealment is enabled.

Abstract: An integrated air/fuel sensor is disclosed for use with a gaseous fuel internal combustion engine. The sensor includes a housing having a mass air flow sensor which provides an output signal representative of the mass of air flow through the mass air flow sensor. Similarly, a mass gas sensor is also contained in the housing which provides an output signal representative of the mass of gas flow through the mass gas flow sensor. The integrated air/fuel sensor is mounted to the air and fuel supply system for the engine upstream from the internal combustion engine. The output signal from both flow sensors are provided as input signals to a circuit which calculates the air/fuel ratio to the engine and provides an output signal representative thereof to the fuel management system for the engine.

Abstract: A fuel management system is provided for use with an internal combustion engine which utilizes gaseous fuel as the fuel source. A mass gas flow sensor is fluidly connected between the gaseous fuel source and the engine. A mass air flow meter is similarly provided in series with an air intake for the internal combustion engine and the outputs from both flow meters are provided as input signals to a microprocessor based control circuit. The control circuit calculates the air/fuel ratio of the combustible charge provided to the engine and generates appropriate output signals to a valve arrangement in series between the source of gaseous fuel and the internal combustion engine to vary the air/fuel ratio to obtain a desired engine performance as a function of the engine operating condition. An air/fuel ratio sensor is also in fluid communication with the exhaust gas stream from the engine and provides an output signal representative of the actual air/fuel ratio to the control circuit.