Memory access modes for a video display generator
First Claim
1. In a data processing system, having a display system, the display system which includes a central processing unit (CPU) producing data, address and control binary signals, and a display memory for storing binary signals representing information to be displayed, said display memory comprising:
- (a) first random access storage means for storing binary dot information;
(b) second random access storage means for storing binary behavior information;
(c) third random access storage means, operatively connected to said first storage means, for storing binary characteristic information, said first, second, and third storage means each having "m" addressable storage locations with each addressable storage location storing "n" bits, where "m" and "n" are integers other than zero, each of said first, second, and third storage means having address terminals operatively connected to a display address bus for receiving concurrently binary address signals representing the addressable storage location from said CPU; and
(d) control logic means, having input terminals for receiving selected address signals, data signals, and control signals from said CPU, said control logic means being operatively connected to said first, second and third storage means for generating chip enable control signals said chip enable signals having a predetermined value enabling the storage means to store data signals produced by the CPU in an addressed memory location of the enabled first, second, or third storage means, the chip enable signals having said predetermined value being determined by the address, data, and control signals produced by said CPU and applied to said control logic means.
1 Assignment
0 Petitions
Accused Products
Abstract
A display memory which stores information to be displayed on a raster scan CRT comprises a first storage element for storing dot information, a second storage element for storing behavior information, and a third storage element for storing characteristic information. The first, second, and third storage element are each arranged in an nxm plane where m is an addressable location and each addressable location within each plane has n bits of information. Further, each of the first, second, and third storage elements has address terminals each operatively connected to a display address bus adapted to receive address information from a CPU.
Control logic receives address signals, data signals, and control signals from the CPU. The control logic generates enable control signals to selectively enable access to predetermined combinations of said first, second, and third storage elements in response to the address, data, and control signals from the CPU.
29 Citations
12 Claims
-
1. In a data processing system, having a display system, the display system which includes a central processing unit (CPU) producing data, address and control binary signals, and a display memory for storing binary signals representing information to be displayed, said display memory comprising:
-
(a) first random access storage means for storing binary dot information; (b) second random access storage means for storing binary behavior information; (c) third random access storage means, operatively connected to said first storage means, for storing binary characteristic information, said first, second, and third storage means each having "m" addressable storage locations with each addressable storage location storing "n" bits, where "m" and "n" are integers other than zero, each of said first, second, and third storage means having address terminals operatively connected to a display address bus for receiving concurrently binary address signals representing the addressable storage location from said CPU; and (d) control logic means, having input terminals for receiving selected address signals, data signals, and control signals from said CPU, said control logic means being operatively connected to said first, second and third storage means for generating chip enable control signals said chip enable signals having a predetermined value enabling the storage means to store data signals produced by the CPU in an addressed memory location of the enabled first, second, or third storage means, the chip enable signals having said predetermined value being determined by the address, data, and control signals produced by said CPU and applied to said control logic means. - View Dependent Claims (2, 3, 4, 5, 6)
-
-
7. In a data processing system, having a display system having a raster scan CRT having pixels, the display system which includes a central processing unit (CPU) producing data, address, and control, signals and a display memory for storing binary signals determining the color and intensity of the pixels of the CRT as they are scanned, said display memory comprising:
-
(a) first random access storage means for storing dot information as binary signals; (b) second random access storage means for storing behavior information as binary signals; (c) third random access storage means operatively connected to said first storage means for storing characteristic information as binary signals, said first, second and third storage means having at least one memory plane with each memory plane having "m" addressable data storage locations with each storage location storing "n" data bits, where "m" and "n" are integers other than zero, each bit stored in each addressable location of said third storage means when utilized determining the display of a pixel having the same address and wherein all "n" bits of the corresponding "m" addressable locations of said first and second storage means determine the display of "n" pixels having the same address when utilized and determining whether the signals from the third, or first and second storage means have priority for display and further wherein each of said first, second and third storage means has address terminals each operatively connected to a display address for receiving address signals produced by said CPU; and (d) control logic means, having input terminals for receiving address signals, data signals, and control signals from the CPU, said control logic means operatively connected to said first, second, and third storage means, for generating chip enable control signals to selectively enable data to be written into addressed storage locations of predetermined combinations of said first, second, and third storage means responsive to predetermined values of the address, data and control signals produced by the CPU. - View Dependent Claims (8, 9, 10, 11, 12)
-
Specification