Computer with adaptable video circuitry
US5151997A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 10, 1989 |
| Grant date | Sep 29, 1992 |
| Priority date | — |
| Expiry date | Aug 10, 2009 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG09G2360/125
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A computer which provides a video signal for display is disclosed. The computer has a central processing unit (CPU) which executes a program to provide video data for a display which is organized as a matrix of pixel elements, each pixel element being represented by a certain number of bits of video data stored within a random-access memory (RAM) in the computer. A video integrated circuit is coupled to the RAM to provide N bits of video data per pixel to the display at a dot clock rate consistent with the requirements of the display. This video circuit, rather than having its own video RAM, shares the system memory (i.e., RAM) with the CPU. A memory controller arbitrates access to the RAM between the CPU and the video circuit in a manner that denies access to the RAM by the CPU whenever the video circuit is reading video data from the RAM. All of the video circuitry is incorporated on a single printed circuit board with the rest of the computer circuitry, thereby obviating the need for a separate video card with its own expensive video RAM, and permitting access to the video data at a substantially faster rate than that of past systems.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.