JPS60144789A - Character/graphic display controller - 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 control device capable of displaying characters and graphics in each area.

Conventionally, this type of display sterilization device has used a pit map control system as shown in FIG.

In this circuit, the total g#! Reference numeral 100 writes character or graphic patterns directly into the video memory 111 by area.

The bits in the video memory 111 correspond one-to-one to one pixel on the display screen, and are read out one after another in an order corresponding to scanning of the device and displayed on the display device 103.

This method handles characters as they are as patterns, so there is more information to be processed than when they are expressed in codes, and this method has the disadvantage that the processing speed for character convolution and updating in the video memory is slow. For example, when displaying kanji, the kanji JIS code is expressed in 2 bytes, or the size of the letter pattern is The length is 72 bytes, and the number of information to be processed is 36 compared to the JIS code.
It will be doubled.

In order to solve this drawback, in recent years a system has been adopted that includes a code memory 101 and a character generator 102 in addition to the video memory 111, as shown in FIG. Computer 100 writes the character code into code memory 101. The code No. 11 read out from the code memory 101 corresponding to the display position on the screen is converted into a character pattern by the character generator 102 and output as a character display. The display patterns read from the character generator 102 and the video memory 111 are Lt-registered by the superimposition circuit 121 and displayed. Therefore, in order to display characters and figures in separate areas, it is necessary to erase the contents of the code memory 101 outside the character display area, and also erase the contents of the video memory 111 outside the figure display area. be. In this method, when the character display area is changed to another position on the screen, the content of the video memory ill of the area to be moved is erased, and the character code is stored in the code memory 101 of the area of #work. The disadvantage is that the process of changing the position of the character display area is complicated, such as erasing the code of the original area and, if necessary, re-enlightening the graphic pattern that was the background of the half area before the movement. But it was 19.

Therefore, an object of the present invention is to solve the drawback of the slow processing speed of character information found in the bitmap sideways method when displaying characters in a fixed format in each area, and also to instantly change the position of the character display area. The object of the present invention is to provide a character/graphic display control device that can be changed to a character/graphic display control device.

According to the present invention, it has both a character display section using a code memory and a character generator, and a graphic display section using a video memory, and further generates an area signal specifying the position and size of the area within the display area of the display device. A character/figure display section device is obtained which has an area signal generating means and a selection means for switching and displaying a character display and a figure display inside and outside the area (according to the number M).

Next, the present invention will be described in detail with reference to the drawings showing one embodiment of the present invention.

In FIG. 3, the character/figure display side (incorporated) device includes a code memory 101, a character cinerator 102, a video memory 11, an area signal generation means 1311 and a selection means 1.
33.

The code memory 101 has a temperature meter of $910 via the signal line 163.
Character code from 0 to 1. The character code written to the output line 123 is output according to the read address on the address 142. Character generator 102 receives character code 123, converts it into a character pattern, and outputs it on output line 134 as a character display signal. Video memory 1
11 has a graphic pattern written therein from the computer 100 via the signal line 164, and outputs a graphic display signal to the output line 135 in accordance with the read address on the address line 144. The area signal generation circuit 131 receives the area information from the controller 100 via the signal 1162 and outputs the area signal to the output line 132 in response to the screen synchronization signal on the signal line 152. In accordance with this area newsletter 132, the selection circuit 133 outputs either the character display 1N number 134 or the graphic display signal 135 to the 1g line 136 as the display butter/. The display device 103 displays the display signal 136 on the screen in synchronization with the screen synchronization of the Jυ1v1 line 152. The screen synchronization signal 152 is generated by the screen synchronization signal generation circuit 151 and is also input to the read address circuits 141 and 145. The read address circuits 141 and 145 have a total of n
The seven addresses are read from each code memory 10 at the timing according to the screen cycle signal starting from the successive start address given by the signal lines 165 and 166 from the machine 100, respectively.
1, and output to the video memory 111.

The operation of this embodiment will be explained below. Display device 10
3 displays an image while scanning the area on a CRT (CRT). That is, the screen is made up of a plurality of scanning lines, and each scanning line is a collection of a series of pixels (hereinafter referred to as dots). This scanning control is performed using horizontal and vertical synchronizing signals that define the area scanning timing and a dot clock signal that defines the dot display timing. These signals are the screen synchronization 1g number 152.

The display signal 136 is a graphic pattern read from the video memory 111, or a dot signal in which character patterns output from the character generator 102 are arranged in series along the running direction.

141.145 indicates. Read address circuit 141
, 145 sequentially update and output addresses based on the vertical synchronizing signal V (based on the read start address designated by the computer 100).

The area 46 No. 132 is generated by the area signal generation circuit 131 in synchronization with the screen synchronization (the computer 100 is also designated based on the ti No. 152 f?:) and the timing corresponding to the area. For example, as shown in FIG. If the area designated by is a rectangle, the display address of the upper left point and lower right point of the rectangle becomes the area information.

The area signal generation circuit 131 outputs 1'' as an area signal while scanning the rectangular area during the surface scanning operation, and outputs '0'' in other areas.

A selection circuit 133 receiving the area signal 132 outputs a character screen signal 134 when the area 132 is 1'', and outputs a graphic screen signal 135 when it is 0''.

This situation is shown at 1328 and 13b in FIG. As a result, it is possible to fit the character display 134 into the rectangular area 139 of the graphic display 134.

The position of the fitting region can be changed instantaneously by simply updating the region information given to the region signal generation circuit 131. At this time, by simultaneously changing the read start address given to the read address circuit 141 by an address corresponding to the change in the fitting position, it is also possible to make it appear that the character display contents in the fitting area do not change. That is, as shown in FIG. 5, the reading start address is set to the character rA.
By changing the size of ΔDP from the address of J to the address of the character rEJ, it can be seen that φ can move the position of the display area of rBcJ. As a result, it is not necessary to erase the video memory 111 of the new fitting area or rewrite the graphic pattern of the old fitting area when the position of the fitting area 132b is moved. Also, there is no need to transfer the contents of the code memory.

In this embodiment, an example is shown in which characters are displayed in the fit-in area 132b, but it is also possible to display a figure in this area 132b. That is, in this case, the selection circuit 133 selects the graphic signal 135 when the area signal 132 from the area signal generation circuit 131 is N I I+. ′
O'', the character signal 134 may be outputted to the output line 136. At this time, the read address 144 of the graphic pattern is changed by changing the read address of the address circuit 145.

As described above, the present invention has the effect of enabling high-speed writing and updating of characters and instantaneous change of character display position by providing a circuit for specifying a fitting area.

[Brief explanation of the drawing]

1 and 2 are diagrams showing an example of a conventional character/figure display side diagonal device, FIG. 3 is a diagram showing an embodiment of the present invention, and FIG. 4 is a diagram showing the operation of the area signal generating means and the selection circuit. A diagram showing
FIG. 5 is a diagram showing the shift of display contents. 100...Total xi, 1o 1...Code memory, 102...Character generator, 103...Display device, 111...Video memory , 121...superposition circuit, 131
..... Area signal generation circuit, 132 ..... Area signal, 133 ..... Selection circuit, 141°145
...Read address circuit, 151...
Screen synchronization signal generation circuit. 5th area

Claims (3)

[Claims] (1) A video memory that stores pixel information displayed as a graphic display on a display device, a code memory that stores codes of characters in a character display that is displayed on the display device, and the characters read from the code memory. a character generator that converts a code into pixel information of a character pattern; an area signal generating means that generates an area signal that specifies a position and size area within the display area of the display device; A character/graphic display control device comprising: a selection means for switching between the character display and the graphic display for display output. (2) The character/figure display side leg device according to claim 1, further comprising a read address circuit for changing a read start address of the code memory. (3) The character/graphics display control device according to claim 1, further comprising a read address circuit for changing a read start address of the video memory.