Mixed format video ram

• US 5,644,336 A
• Filed: 12/12/1994
• Issued: 07/01/1997
• Est. Priority Date: 05/19/1993
• Status: Expired due to Term

• Current Assignee: Taiwan Semiconductor Manufacturing Company Limited
• Original Assignee: AT&T Global Network Services LLC (AT&T, Inc.), Symbios Logic Incorporated (Broadcom, Inc.), Hyundai Electronics America Incorporated (SK Hynix Inc.)
• Inventors: Herbert, Brian K.
• Primary Examiner(s): Hjerpe, Richard
• Assistant Examiner(s): Stoll, Kara Farnandez
• Application Number:
  US08/355,413
• Time in Patent Office: 932 Days
• Field of Search: 345/153, 345/154, 345/155, 345/186, 345/187, 345/188, 345/113, 345/115, 345/116, 345/199, 345/118, 345/119, 345/120, 345/132, 345/189, 345/190, 345/196, 345/201, 345/203, 395/154, 395/157, 395/163, 395/164, 348/589, 348/600, 348/716
• US Class Current: 345/603
• CPC Class Codes: G09G 2340/125 wherein one of the images is motion video
• CPC Class Codes: G09G 5/02 characterised by the way in which colour is displayed details of colour display specific for CRTs G09G1/28; specific for flat matrix panels other than liquid crystal displays G09G3/2003; specific for liquid crystal displays G09G3/3607
• CPC Class Codes: G09G 5/06 using colour palettes, e.g. look-up tables
• CPC Class Codes: G09G 5/395 Arrangements specially adapted for transferring the contents of the bit-mapped memory to the screen G09G5/399 takes precedence
• CPC Class Codes: H04N 9/641 Multi-purpose receivers, e.g. for auxiliary information H04N9/642 takes precedence
• CPC Class Codes: H04N 9/67 for matrixing camera processing pipelines for matrixing of colour signals H04N23/85

Abstract

The invention concerns the simultaneous display of video data and text data on a computer display. The invention stores both types of data in display memory. Transition codes mark the separation between the two types. The invention converts each type of data into signals which a CRT display can understand. The invention changes the type of conversion, as appropriate, when transition codes are reached.

Claims

1. In the process of storing data into a display memory in a computer, the improvement comprising the following step:

storing a unique code in the display memory between data of a first type corresponding with at least one video display pixel and successive data of a second type corresponding with a plurality of video display pixels, said unique code marking a transition point wherein video data stored in the display memory changes from a first display image format to a second display image format and wherein said successive data is for use to generate said plurality of video display pixels according to said second display image format.

2. In a video display system, which translates data stored in a display memory into a video image, said data comprising a plurality of data types which represent dissimilar display image formats, the improvement comprising the step of:

changing to a different method of stored data translation when a predetermined code word is detected between data of a first type corresponding with at least one video display pixel and successive data of a second type corresponding with a plurality of video display pixels in the display memory, wherein said successive data is for translation to generate said plurality of video display pixels according to a display image format corresponding with said second data type.

3. In a computer having a video controller which provides CRT input to a display, based on video data contained in a display memory, the improvement comprising:

(a) a transition code between low-overhead data corresponding with at least one video display pixel, and successive high-overhead data corresponding with a plurality of video display pixels in the display memory;

(b) means for reading the display memory and for detecting the transition code;

(c) means for translating high-overhead data into low-overhead data;

(d) means for activating said means for translating high-overhead data when the means for reading detects the transition code, so that said successive high-overhead data read from the display memory subsequent to the detection of the transition code is translated into low-overhead data, wherein said successive high-overhead data is for use to generate said plurality of video display pixels according to a corresponding display image format, said high-overhead data comprising a greater number of bytes per pixel than said low-overhead data; and

(e) means for translating said low-overhead data into CRT input.

4. A method of operating a video controller, which provides CRT input to a CRT, comprising the following steps:

(a) reading data from a display memory, said data comprising a plurality of data types which represent dissimilar display image formats;

(b) deriving CRT input, corresponding with at least one video display pixel, in a first manner associated with a first display image format, using the data read; and

(c) monitoring the data read and, when a predetermined data word is detected, deriving CRT input in a second manner associated with a second display image format for successive data, corresponding with a plurality of video display pixels, read from said display memory after said predetermined data word is detected, wherein said successive data is for use to generate said plurality of video display pixels according to said second display image format.

5. A method of controlling a video display, comprising the following steps:

(a) reading video data from a video memory, said video data comprising a plurality of data types which represent dissimilar display image formats; and

(b) monitoring the video data, and, when a predetermined data type occurs, translating subsequent successive video data, corresponding with a plurality of video display pixels, from the video memory into a different display image format, wherein said successive video data is for use to generate said plurality of video display pixels according to said different display image format.

6. A method of generating a video image in a computer, comprising the following steps:

(a) embedding a transition code within a display memory, said transition code indicating a transition from one type of data to another type of data;

(b) reading data from said display memory;

(c) generating pixels based on said data read from said display memory;

(d) detecting the occurrence of said transition code in said data read from said display memory;

(e) generating a pixel using said transition code; and

(f) generating subsequent pixels based on data outside said display memory wherein said pixel generated using said transition code is between said pixels generated based on data from said display memory and said pixels generated based on data outside said display memory.

7. A process for generating multiple image types on a computer display, comprising the steps of:

storing at least one data word having a first data format in a display memory, said at least one data word to be used to create at least one pixel of a first type on said computer display;

storing a transition code word in a location in said display memory after said at least one data word;

storing successive data words having a second data format in a location in said display memory after said transition code word, said successive data words to be used to create a plurality of pixels of a second type on said computer display;

using said transition code word as an indicator, while reading from said display memory, that the data words being read are transitioning in data format; and

processing said data words read from said display memory according to data format to create images of multiple types on said computer display.