JPS62134686A - Display unit - 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 device used in personal computers, word processors, and the like.

Conventional technology fA of read/write memory (hereinafter abbreviated as RAM)
With the decline in t&, image memory (hereinafter referred to as VRAM) that stores pixel information for each display dot of a cathode ray tube (hereinafter referred to as CRT) has come to be used in display devices. .

FIG. 2 is a block diagram of a conventional display device.

1 is a central processing unit such as a microprocessor (CPU)
), and a display control device (hereinafter abbreviated as CRT C) 2 and a VRA are connected to the pass line of the CPU 1.
M3 is connected. Then CR'I''C2 to V
Control signals are manually input to RAM3.

Further, the data from the VRAM 3 is converted into serial data by the shift register 4 and sent to the display control device 5. Further, a control signal is sent from the CR''I''C2 to the display control device 5, and CRT6z image information is sent from the display control device 5.

Since the conventional display device is configured as described above, V
The image data stored in RAM 3 is sent to CR'I'' 6 via shift register 4 and display control device 5.

Problems to be Solved by the Invention When changing part of the image on the CRT 61, the conventional display device changes part of the data on the VRA MJ corresponding to the changed part of the image on the CRT 6. I had to.

For example, when moving the cursor on a CRT6,
The CPU needs to rewrite the data corresponding to the cursor in the image data on VRAM3 one after another, and the CPU
There was an inconvenience that U1 was occupied by this rewriting operation.

For example, assume that a CRT 6-hi has a string of letters ABCD. The cursor is on A of this string of letters, and when you try to move the cursor to the hill of B,
First, the CPU creates a dot pattern of the letter A with black and white reversed inside the frame and stores it in VRAM3.Next, the CPU creates the normal character ``and'' creates a dot pattern of the letter B with black and white reversed inside the frame. I created it and put it in VRAM3 (it was operating like 111).

Means for Solving the Problems In order to solve the above-mentioned problems, the present invention provides an image memory for storing image data, and a change memory for storing data that can be replaced with a part of the data in the image memory. A memory, an operation start address register that stores address data that does not indicate the location where data stored in the modification memory will be replaced with part of the data stored in the image memory, and A portion of the data stored in the memory for modification is inserted into the performance 1T%
It consists of a device that performs operations.

Operation With the above configuration, the present invention stores the image data to be changed in the change memory and replaces it with the data in the VRAM by the arithmetic unit, so that the CPU is not occupied by rewriting the data in the VRAM. .

Embodiment FIG. 1 is a block diagram of an embodiment of the display device of the present invention.

Here, the same parts as in the conventional display device described above are given the same numbers, and the explanation will be omitted.

Reference numeral 7 denotes an operation start address register, which stores the address on the VRAM 5 of data to be replaced.

Reference numerals 8 and 9 indicate memory for modification, which stores image data to be replaced.

Numerals 10 and 11 are arithmetic devices that calculate data in the change memories 8 and 9 and send the data to the display control device 5.

The present invention has the above-described configuration, and an example in which the cursor is moved over the character string ABCD will be described in the same manner as in the conventional example described above.

First, the image data stored on the VRAM 5 is stored in the arithmetic unit 1.
0.11 to the shift register 4, changed to serial data, sent to the display control device 5, and visually displayed on the CRT 6.

Here, if you try to replace part of the image data displayed on the CRT 6 with other image data, i.e., move the horn over the string of letters AB CD, the image data to be replaced, i.e., the letter L. The normal image data of \ is stored in the changing memory S.\, and the black and white inverted image data is stored in the changing memory 9. Then, the address of the track data to be replaced, that is, the address to the character, is entered in the address register 7, and the command to replace the image data is issued by the CP Ul.

Then, among the image data on VR and AMS, rif
i The data specified by the address data stored in the nose start address register 7 is replaced with the data stored in the change memory 8゜9 by the one-ohm device 1flo, 11, and the shift register 11 and display control It is displayed on the CRT 6 via the device 5.

Then, if the image data related to the character B is stored in the changing memory 8.9, the CPU simply stores the changing memory 8.9.
, 5a and the data in VRAM3, the cursor can be moved, and the movement of the cursor does not occupy the entire operation.

In this way, the present invention includes two changing memories 8, 9, and two arithmetic units ei, 10, 11;
Therefore, when displaying moving image data such as a horned crane on CI<'F6, one of the changing memories 8 (the stored image data is
0 allows the next changing image data to be prepared in the other changing memory 9 while the image data is being sent to the shift register 4, and the CPU is not occupied by changing the image data.

The above explanation has been given by taking the movement of a horn as an example. A modification memory that stores data that will be replaced with part of the data stored in the image memory, and address data that indicates the location where the data stored in the modification memory will be replaced with part of the data stored in the image memory. It consists of a 7' trace register, which performs arithmetic processing to replace part of the data stored in the image memory with data stored in the change memory, and an arithmetic unit iA, which performs arithmetic processing to replace part of the data stored in the image memory with the data stored in the change memory, so it changes to the change memory. Image data is stored and replaced with data in VRAM by the arithmetic unit, so the CPU is not occupied with rewriting data in VRAM.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of the display device of the present invention, and FIG. 2 is a block diagram of a conventional display device. 1...CPU 2...CRTC3...VR
AM4...Shift register 5...Display control device 6...CRT? ...Calculation start address register 8.9...Memory for modification 10.11.
...Name of computing device agent Patent attorney Toshio Nakao Haka1
Name xie −

Claims (1)

[Claims] an image memory that stores image data; a display device that visually displays the data in the image memory; a change memory that stores data to be replaced with part of the data in the image memory; and a change memory that stores data in the change memory. an arithmetic start address register that stores address data indicating a location where the data to be replaced is to be replaced; and an arithmetic device that performs arithmetic processing to replace part of the data stored in the image memory with data stored in the change memory. A display device characterized by the following.