JPS58196584A - Display indication system - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a display display system, and particularly to a refresh memory, character generator memory, and graphic memory control system for a raster scan display device. In the case of a display device, the structure is as shown in FIG. 1, and in the case of a graphic display device, as shown in FIG. In the case of a character display device, the refresh memory address signal 11 output from the display timing generation circuit 5 is sent to the address selector circuit 3 which selects either the externally applied fresh memory address signal 12 or the refresh memory address signal 11. The character/graphic code to be input to the refresh memory 1 and displayed is read out. The read or fresh memory output signal 13 is input to the character generator memory 2, reads out the display pattern signal 14, and is converted into a video signal 15 by the parallel-to-serial conversion circuit 4.In the case of a graphic display device, the display The character symbol or figure pattern to be displayed is directly loaded into the graphic memory 6, the display pattern signal 14 is read out using the graphic memory address signal 17 from the display timing generation circuit 5, and the video signal is converted into a video signal by the parallel-to-serial conversion circuit 4, similar to a character display device. It was converted to 15.

However, such conventional devices have the drawback that even if you try to make the display device operate as a character display or a graphic display, it is impossible to do so, narrowing the range of application. This has the disadvantage that two circuits must be provided, resulting in increased costs.

The present invention has been made to solve these drawbacks. Therefore, an object of the present invention is to provide a general-purpose memory having the function of storing character symbol codes, character symbol patterns, or graphic patterns to be displayed. It is therefore an object of the present invention to provide a novel display device that can arbitrarily change the memory function according to the purpose using external signals. A general-purpose memory equipped with a refresh memory function for storing character symbol codes to be displayed, a character generator memory function for storing character symbol patterns, and a graphics memory function for storing graphic patterns is provided, and means for selecting the memory functions from the outside is provided. This is achieved by a display device characterized in that the display device can be arbitrarily selected as a character display device or a bluff run display device as required by growing the display device.

Hereinafter, a preferred embodiment of the present invention will be explained in detail with reference to the drawings. Fig. 3 is a block diagram showing an embodiment of a display device to which the method of the present invention is applied; Fig. 4 (2); 3 is a time chart showing the operation of the display device shown in FIG. 3;

In Figure 3, the same reference numbers as in Figures 1 and 2 refer to 1.
Reference numeral 7 indicates the same elements as shown in FIG.
is a general-purpose memory according to the present invention, and 8 is a key “nead” L/
9 is a general-purpose memory 871 address selector circuit, 10 is a display timing generation port, and 18 is a memory content decoder. A general-purpose memory address signal 19 outputted from the circuit 10 is input to the general-purpose memory 7, the general-purpose memory data is read out, and a memory content decoder 18 determines what purpose the general-purpose memory 7 is used for.

If it is used as refresh memory, the fourth
As shown in Figure (2) K, the general-purpose memory data is transferred to the character generator edge 8, and inputted again to the general-purpose memory 7 via the general-purpose memory address selector circuit 9 as a character generator address signal, and the data necessary for display are Read character pattern. In addition, in Fig. 4 (2),
Reference numeral a indicates a character clock period, b indicates a refresh memory area read period, and C indicates a character energy area read period.

On the other hand, if it is used as a graphic memory, as shown in FIG. 4 (BIK), the general-purpose memory data 20 is directly latched to the parallel-to-serial conversion circuit 4 and output as a video signal. It shows the graphic memory area read period.

As explained above, the present invention has the advantage that the display device can be used both as a character display and as a graphic display by configuring the general-purpose memory 7 so that it can be used as either a recipe memory, a character generator memory, or a graphic memory. There is an economic advantage in that a character Taguchi quick display device can be easily configured with a minimum memory configuration.

The present invention has been described above with respect to one preferred embodiment thereof, but
These are merely illustrative, and it goes without saying that the present invention is not limited only to the embodiments described here.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a conventional character display device, FIG. 2 is a block diagram of a conventional graphic display device, FIG. 3 is a block diagram of a display device to which the display method of the present invention is applied, and FIG. ),
(2) is a time chart showing the operation of the display device of the present invention, (2) is when it operates as a character display, and (2) is a time chart when it is operated as a graphic display. 1... Refresh memory, 2 ...Character generator memory, 3...Address selector circuit, 4...Parallel-serial conversion circuit, 5...
... Display timing generation circuit, 6 ... Hegela quick memory, 7 ... General purpose memory, 8 ...
... Charging energy address latch, 9 ... General purpose memory address selector circuit, 10 ... Display timing generation circuit, 11 ... Refresh memory address signal, 12 ... ...Receipt memory address signal from outside, 13...Refresh memory output signal, 14...Display pattern signal, 15...Video signal, 16... ...Synchronization signal, 17...Graphic memory address signal, 18...Memory content decoder, 19...
・General-purpose memory address signal, beauty... General-purpose memory data patent applicant NEC Corporation Representative Patent attorney Yutabe Kumagai Figure 1 @ Figure 2 Figure 3 (A) Figure 4

Claims (1)

[Claims] A display device that displays character symbols and figures on a display screen, which is equipped with a refresh memo 9 function for storing character symbol codes to be displayed, a character generator memory function for storing character symbol patterns, and a graphic memory function for storing figure patterns. It comprises a general-purpose memory, a selection means for selecting the memory function of the general-purpose memory (externally), and a display means for displaying a screen according to the selected function, and the display device can be a character display device or a graphic display as necessary. A display device characterized in that it can be arbitrarily selected and used as a device.