Method and apparatus for auto-generation of horizontal synchronization of an analog signal to a digital display
AssigneeGenesis Microchip Inc.
InventorGreg Neal
Life of this patent
Estimating the term…
Abstract
A method, apparatus, and system for determining a true horizontal resolution of an analog video signal arranged to display a number of features having associated feature edges on a display each of which were created with a true pixel clock is described. For a test horizontal resolution, if it is determined that substantially all of the feature edges have substantially the same phase relationship to a test pixel clock, then the test horizontal resolution is the true horizontal resolution.
Claims26
A method of determining a true horizontal resolution of an analog video signal arranged to display a number of features which, when taken together, form a displayed image, the features having associated feature edges on a display each of which were created with a true pixel clock, the method comprising:
- for a test horizontal resolution,
- determining if a minimum predetermined number of the feature edges have the same phase relationship to a test pixel clock, then the test horizontal resolution is the true horizontal resolution.
An apparatus for determining a true horizontal resolution of an analog video signal arranged to display a number of features which, when taken together, form a displayed image, the features having associated feature edges on a display each of which were created with a true pixel clock, the method comprising:
- for a test horizontal resolution,
- means for determining if a minimum predetermined number of the feature edges have the same phase relationship to a test pixel clock, then the test horizontal resolution is the true horizontal resolution.
An analog video signal synthesizer unit, comprising:
- a video signal oversampling unit arranged to oversample a video signal by an oversampling factor n, the video signal arranged to display a number of features which, when taken together, form a displayed image, the features having associated feature edges each of which were created with a true pixel clock;
- a full display feature edge detector unit coupled to the video signal oversampling unit arranged to provide information used to calculate a horizontal resolution value (HTOTAL) corresponding to the video signal, wherein the full display feature edge detector unit detects positive rising edges of a number of displayed features;
- a temporal spacing calculator unit coupled to the full display feature edge detector unit that uses the detected feature edges to calculate an average temporal spacing value associated with the detected feature edges;
- and
- a horizontal resolution calculator unit coupled to the temporal spacing calculator unit that calculates the horizontal resolution based upon a sample clock frequency fsample provided by a clock generator unit coupled thereto and the average temporal spacing value when the average temporal spacing value is about equal to the oversampling factor n.
Dependencies are inferred from the claim text.