The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 05, 1995
Filed:
Oct. 19, 1993
Chrontel, Inc., San Jose, CA (US);
Abstract
A RAMDAC circuit drives a display device so as display multiple modes of color depth and display resolution in a single display frame without sacrificing resolution of the higher-resolution mode, and adjusts the output pixel rate to match that of the display mode being display on a pixel-by-pixel basis. The RAMDAC circuit switches between two graphics modes on-the-fly on a pixel-by-pixel basis in accordance with mode control bits stored in the pixel data. Furthermore, the RAMDAC circuit switches between two output pixel rates such that the amount of video memory used for any predefined screen area remains constant even though the output pixel rate and resolution are dynamically adjusted. In a preferred embodiment a display mode signal is embedded in the display data such that the display data, including the mode signal, comprises one byte of data for each display pixel when the mode signal specifies the first display mode, and comprises two bytes of data for each display pixel when the mode signal specifies the second display mode.