Abstract: A method and corresponding structure for shielding a floating gate tunneling element. The method comprises disposing a floating gate over a gate oxide using standard CMOS processing in two active areas defined by first and second doped well regions formed in a substrate surrounded by field oxide, and forming a floating gate shield layer so as to enclose the floating gate. The floating gate includes a first floating gate portion over an active area in the first doped well region and a second floating gate portion over the active area in the second doped well region. The first floating gate portion is substantially smaller than the second floating gate portion so as to enable adequate voltage coupling for Fowler-Nordheim tunneling to occur between the first doped well region and the first floating gate portion. The direction of tunneling is determined by high voltage application to one of the doped well regions.

Abstract: A method and apparatus for the extraction of luminance information from an analog composite video signal. Non-luminance information in the video signal is 180.degree. out of phase between adjacent lines in adjacent fields of a video signal. Appropriately filtered adjacent fields are summed to cancel non-luminance information, leaving the desired luminance information. A field store is employed to allow the summing of adjacent fields by storing the present field to be summed with the next field of the video signal.

Abstract: A digital chrominance signal in a digital component television system is digitally filtered to obtain sampling values intermediate the sampled values obtained during analog to digital conversion of the chrominance signal, such that the resultant number of chrominance samples per second in the digitized chrominance signal corresponds with the number of luminance samples per second in the digitized luminance signal. The samples values of the digitized chrominance signal including the computed intermediate values may also be modified by said digitized filter to minimize the alias created by the analog to digital correction sampling process, to compensate this signal for sine x/x losses existing in the digitized chrominance signal, to compensate for Gaussian filter attenuation of the chrominance signal prior to analog to digital conversion thereof, and to compensate for other deficiencies in the chrominance signal.

Abstract: Time base errors in PAL subcarrier reference bursts, created in part by the operation of a video tape recorder, are detected by the recorder and used for detecting the phase shift error in PAL phase angle switching between bursts on adjacent video signal lines which existed before the video signal was recorded. The video tape recorder timing errors detected on the PAL bursts are first detected after the 90.degree. phase angle between successive PAL bursts has been eliminated. Two sample and hold units then are alternately strobed, each at a point in time during a given tape recorder head pass wherein the error signals are normally most accurate, such that a first burst timing error is retained in one such unit and a next burst timing error is retained in said second unit. The outputs of these two sample and hold units are filtered and combined in an integrator for generating a voltage control signal whose amplitude varies as a function of the pre-existing burst shift error.

Abstract: A system for transmitting an audio signal in pulse width modulated form on a video signal is disclosed. The audio signal is modulated by varying the time occurance of at least one edge of a pulse as a function of the voltage level of said audio signal at a selected time. The pulse is then added to the video signal during each horizontal blanking interval. Upon receipt of the transmitted signal, the video signal is processed to reform said edge varying pulse. An output pulse is then generated for each varying edge of said pulse, whose pulse width is a function of the time of occurance of said edge with respect to a stable reference edge. This output pulse is then used to generate a voltage signal whose level is determined by the pulse width of said output pulse. The successively generated voltage levels comprise the reformed audio signal.