Tektronix International Sales Gmbh

Sony/tektronix Corporation

Tsuyoshi Kitagawa

Norihiko Sato

Digital fine delay processing provides an accurate and continuous delay for an analog signal generated from source digital data. A digital processor generates processed digital data corresponding to a delayed analog signal having a desired delay relative to the analog signal represented by the source digital data. The processed digital data is directly derived from the source digital data by digital processing, and both digital data are processed by a reference clock, or by the same phase and cycle of the reference clock. The processed digital data is converted into a the delayed analog signal. Modifying coefficients in a convolution function performed by the digital processor changes the desired delay so that the delay is accurately controlled and is continuous. Since the entire process is digital, degradation of the delayed analog signal is minimal.

Digital fine delay processing

A waveform monitor receives HDTV and SDTV signals that are provided to a channel and an external trigger terminal respectively. An HDTV signal processor 14 produces a reference clock PCLK from the HDTV signal. A counter starts counting at the vertical sync signal of the SDTV signal and generates a trigger every time the count of the reference clock PCLK reaches a predetermined number (2,200, for example). This allows generation of a trigger signal which is phase locked to the vertical sync signal of the SDTV signal, and of which the frequency is the same as the horizontal line frequency of the HDTV signal. Therefore the waveform monitor can display the HDTV waveform line by line even though the HDTV and SDTV signals have different numbers of lines per field. The waveform monitor can be used to measure phase difference between television signals of difference formats, such as the HDTV and the SDTV.

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Tokyo, Japan

Tsuyoshi Kitagawa