Patent ID: 6014125
Filing Date: 2000-01-11
Classification: G06T,G09G

Abstract:
A horizontal scaling apparatus for horizontally scaling a scan line including a graphics portion and a video portion, the apparatus comprising:a first VCO for generating a first output signal exhibiting a first frequency which is locked in frequency with respect to a reference clock signal;a second VCO for generating a second output signal exhibiting a second frequency which is locked in frequency with respect to the reference clock signal;a third VCO for generating a third output signal exhibiting the second frequency of the second VCO, the third VCO and the second VCO sharing common frequency control information, the third VCO being held in a hold state when a HOLD signal is supplied thereto, the third VCO entering an enabled state to output the third output signal when the HOLD signal is removed;a clock signal selector device, coupled to the first VCO and the third VCO, for clocking a graphics portion of a scan line to a display using the first output signal and for clocking a video portion of the scan line to the display using the third output signal; andscaling devices for selecting the frequency of the second and third output signals according to the amount of scaling desired for the video portion of the scan line.