JPS5981687A - Display - 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 [Technical Field of the Invention] The present invention relates to a display device used in an information processing system, and more particularly to a display device configured to receive a character code from the outside and obtain a character pattern from the character code.

[Technical background of the invention and its problems]

Generally, in an information processing device equipped with this type of CRT display device, when characters (kanji, alphabets, numbers, kana), symbols, etc. are to be displayed on the CRT display device as specified by the CPU, the CPU A code and 1h information of the row 1 digit position to be displayed are sent to the device, and the CRT display device generates and displays four turns of display from the code. At this time, in order to improve the processing performance of the display device,
Dedicated memory (ROM) for the correspondence table between chords and tsuturns.
I have it. However, the dedicated memory in the conventional display device of this type cannot be read and controlled directly by the CPU, and therefore the CPU cannot directly read out the four turns from the dedicated memory. To avoid this, if an image is to be displayed without being taken up in the second row position of the display device, for example, in the case of displaying a mixed pattern of figures and characters, the CPU must prepare the no + turn in advance, or use the code and pattern. It was necessary to create a pattern by placing a correspondence table in a file etc. Therefore, in the past, the CPU was burdened with processing for handling patterns, and the code/pattern correspondence table took up a huge amount of space, resulting in poor utilization of memory, files, etc.

[Purpose of the invention]

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a display device in which a CPU can directly obtain an arbitrary character pattern from a character pattern memory provided in the display device.

[Summary of the invention]

The present invention has a structure in which the character pattern memory provided on the display device side can be directly read and controlled by a specific command from the outside (hereinafter referred to as a read font command). and a pattern output means for outputting a character pattern read from a character nog turn memory to a system path or the like based on the command decoding signal.

When the display control device receives the read font command and the character code from the CPU, the display control device decodes the command, obtains a character code unique to the character code from the character pattern memory, and transfers this character pattern to the CPU. transfer to memory. As a result, the CPU 9 can quickly and easily obtain arbitrary character turn data without having a code/pattern conversion table in the internal memory or file memory.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to the drawings. In the figure, 100 is a CPU that controls the entire system, 101 is a main memory having a program storage area, a work area, etc.;
02 is a system bus. Reference numerals 103 to 109 refer to the display device side (forming the J1 component, 103 is the display control device, 104 is the refresh memory for storing display image data, and 105 is the image data in the refresh memory 104) for real conversion. 106 is a CRT display section for displaying and outputting a pattern according to the video signal; 107 is a CRT control section for controlling the CRT display section 106; 108 is a character.

An address conversion unit converts a code such as a symbol into pattern storage position data (hereinafter referred to as a pattern read address) specific to the code, and 109 is a character A' turn that stores various patterns (bit image data) such as characters and symbols. It's memory.

Further, 20 to 204 constitute components of a read font command control mechanism section provided in the display control device 103, and 20 receives the read font command sent from the CPU10θ via the system bus 102. ,
A command decoder (CD) 202 decodes this, and a flag unit (F') 20 receives and holds a read font command detection signal from the command decoder 201.
3 is a buffer section (BUF) for temporarily storing pattern data read out from the character pattern memory 109; 204 is a buffer section (BUF) for temporarily storing pattern data read out from the character pattern memory 109;
The operation of one embodiment will now be described. CPU100
Okay, when a read font command is sent to the display control device 103, followed by a character code and a pattern write address (on the main memory 101),
This command, character code, and pattern write address are received by the display control device 103 via the system bus 1θ2, and are temporarily stored in an input/output register section (not shown). Then, the command decoder 201 decodes the command and outputs a read font command detection signal, thereby setting the flag unit 202 in a set state. Furthermore, the above character code is sent to the address converter 108, and character/mother turn data specific to the above character code is read out from the character i+turn memory 109 using the pattern read address obtained from the address converter 10g. This character pattern data is sent to the display control device 103 and stored in the buffer unit 203, and then stored in the main memory 101 under the control of the display control device 103 via the router 204 and the system path 102. is written to an address according to the above pattern write address.

In this manner, the CPU 100 can read arbitrary character pattern data from the character pattern memory 109 provided in the display device in response to the read font command.

〔Effect of the invention〕

As detailed above, according to the display device of the present invention, the CP
Since U can directly import any character pattern from the character pattern memory provided in the display device, 9, CP
On the U side, dynamic and quick character pattern processing can be performed without preparing character patterns or having a code/pattern correspondence table.

[Brief explanation of the drawing]

The figure is a block diagram showing one embodiment of the present invention. 100...CPU, 101...Main memory, 102-
・System bus, 103...Display control device, 1os-・
・Address conversion section, 109...Character/gut turn memory, 201...Command decoder, 202...Flag sound doctor 203...Buffer section, 204...Dart.

Claims (1)

[Claims] The host device receives the character code, and the character pattern memory obtains character A turn data specific to the character code;
In a display device that displays and outputs the character pattern data on a display screen, means for receiving a specific command and a character code from the host device and interpreting the specific command;
Based on the interpretation of the specific command, the character pattern data unique to the corresponding character code is obtained from the character pattern memory (the character pattern memory), and the character pattern data is transferred to the memory of the host device. display device.