JPH05313643A - Character attribute synthesizing device of character display device - Google Patents

Abstract

PURPOSE:To facilitate the designing of a circuit which generates attribute data by putting character font data and attribute data by plural bits at a time when character display data are generated. CONSTITUTION:A display address is supplied from a display address generating circuit 11 to a character code memory 12, and the character code of a character corresponding to a display position is read out of the character code memory 12 to a character font data generating circuit 14. An address corresponding to the display position of the character to be displayed, on the other hand, is inputted to an attribute code memory 15 from a display address generating circuit 11 and attribute data corresponding to the character to be displayed are read out to an attribute data generating circuit 16. Then, in synthesizing circuits 171-178, synthesizing source character font data and synthesizing source attribute data, by respective bits, are synthesized to generate 8-bit character display data.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a character display device in an information processing apparatus, which combines character font data and attribute data to generate character display data.

[0002]

2. Description of the Related Art Conventionally, when synthesizing character font data and attribute data to generate display data, as shown in FIG. 7, a character font generation circuit 71 stores a Kanji ROM 72 (character font data is stored The character font data 75, which is parallel data read from a certain memory), is converted into serial data by the parallel / serial conversion circuit 73, and the attribute data generation circuit 74 converts the attribute data into data indicating a display attribute for each dot. Converted 77
The dots were combined in order. (Hereinafter, the character font data and attribute data input to the compositing circuit will be referred to as compositing source character font data and compositing source attribute data, respectively.) Therefore, which dot in the character is changed by the attribute data is The combination source attribute data 77 is set according to the timing when it becomes valid. This conventional technique is similar to the conventional display device having an attribute control function described in the section "Structure" in Japanese Patent Laid-Open Publication No. 60-107696.

[0003]

In the prior art, which dot in a character is changed by the attribute data is set by the timing when the combination source attribute data becomes valid. Therefore, the synthesis source attribute data generation circuit becomes complicated to enable character display with a complicated display attribute, and it is difficult to perform character display with a more complicated display attribute.

Therefore, an object of the present invention is to synthesize display data of characters by simultaneously synthesizing a plurality of bits of character font data and attribute data (data representing a display attribute of a character), and then performing parallel-serial conversion. Is used to simplify the circuit for attribute composition and enable the display of characters with more complex display attributes. Also, when the number of bits of character font data increases Be prepared to respond.

[0005]

According to the present invention, in a character display device in an information processing device, when the display data of the character is generated, character font data and attribute data representing a display attribute of the character are represented by a plurality of bits. It is characterized in that display data is generated by simultaneously synthesizing and then performing parallel-serial conversion.

[0006]

[Function] When generating character display data, a kanji ROM
The character font data is read from the text VRAM as the original character font data, the attribute data is read from the text VRAM to be the original attribute data, and both of them are combined at the same time, and then parallel-serial conversion is performed to generate character display data. To do. As a result, the dots that make up a character can be combined with the attribute data by different combining circuits, so it is only necessary to generate the attribute data for each dot, which simplifies the design of the attribute data generating circuit and makes it possible to display more complicated displays. Characters can be easily displayed by attributes.

[0007]

1 is a block diagram showing an embodiment of the present invention. In this embodiment, it is assumed that the characters displayed are composed of 8 dots in each length and width as shown in FIG. In FIG. 1, 11 is a circuit for generating a display address, 12 is a character code memory in which character codes are stored, 13 is a Kanji ROM in which character fonts are stored,
Reference numeral 14 is a character font data generation circuit that reads the character font data from the character code memory 12 and generates composition source character font data to be sent to the composition circuit, 15 is an attribute code memory in which the attribute data is stored, and 16 is an attribute code. An attribute data generation circuit that reads the attribute data from the memory 15 and sends the combination source attribute data 191 to 198 to the combination circuit. 171 to 178 are attribute combination circuits for respective dots of the same raster address that form a character. Reference numeral 18 is a combination. It is a parallel-serial conversion circuit that converts character display data, which is parallel data generated by the circuit, into serial data, and further performs phase matching with another synchronization signal.

The basic operation of the embodiment will be described below with reference to FIG. First, the display address corresponding to the position of the character to be displayed is supplied from the display address generation circuit 11 to the character code memory 12, and the character code memory 12
The character code of the character corresponding to the display position is read out from the character font data generation circuit 14. Then, in the character font data generation circuit 14, an address to be sent to the kanji ROM 13 is generated from the character code and the raster address supplied from the display address generation circuit 11. Then, the character font data (8 bits) for one character and one raster is read from the Kanji ROM 13 and latched in the character font data generation circuit 14. Up to this point, the process is the same as the conventional technique. Then, the character font data is input to each of the eight synthesizing circuits 171 to 178 one bit at a time. That is, 8-bit data of 8 dots 21 to 28 in FIG. 2 is read from the Chinese character ROM 13, and the data of the dot 21 is input to the synthesizing circuit 171.
The data of 2 is in the composition circuit 172, the data of dot 23 is in the composition circuit 173, and the data of dot 24 is in the composition circuit 17
4, the data of the dot 25 is in the combining circuit 175, the data of the dot 26 is in the combining circuit 176, the data of the dot 27 is in the combining circuit 177, and the data of the dot 28 is in the combining circuit 1.
It is input to 78.

On the other hand, similarly to the character code memory 12, a display address corresponding to the display position of the character to be displayed is input to the attribute code memory 15 from the display address generation circuit 11 and attribute data is generated from the attribute code memory 15. The circuit 16 reads the attribute data corresponding to the character to be displayed. Then, the attribute data is latched in the attribute data generation circuit 16.
After that, the attribute data generation circuit 16 generates the combination source attribute data 191 to 198 for the dots 21 to 28, and the combination circuits 171 to 171 respectively.
178 is input.

Then, the synthesizing circuits 171 to 178 synthesize the synthesizing source character font data and the synthesizing source attribute data for each dot to generate 8-bit character display data. In this synthesizing circuit, the synthesizing source attribute data is used to process the synthesizing source character font data into the following four types.

(1) The character font data is not processed.

(2) Forcibly writing character font data
Processed to 1 ".

(3) Forcibly writing character font data
Processed to 0 ".

(4) Invert character font data.

Therefore, the combination source attribute data input to the combination circuits 171 to 178 are 2-bit data, respectively, and "00" and (2) when the character font data is processed as in (1) above. In case of "0
1 "," 10 "in case of (3)," 1 "in case of (4)
It is assumed to be 1 ".

The character display data generated by the attribute synthesis circuits 171 to 178 is input to the parallel / serial conversion circuit 18, latched in the shift register therein, and converted into serial data by the shift clock. Further, the phase is matched with the display synchronizing signal to form character display data.

Now, taking some attribute displays as examples, how the attribute data generating circuit 16 should generate the synthesis source attribute data will be described.

(A) Vertical line: As shown in FIG. 3, in order to perform an attribute display such that a vertical line (vertical line) is displayed by superimposing it on a character, information of attribute data on the vertical line is input to the attribute composition circuit 175. Reflected to only the synthesis source attribute data 195, so that the synthesis source attribute data 195 is “01” when the attribute data regarding the vertical line is active, and is always “00” except for the synthesis source attribute data 195. The attribute data generation circuit 16 may be configured. In the prior art, the attribute data generation circuit must be designed in timing so that the dot data of a character is forcibly processed into "1" only at the timing of attribute combination of dots 25. However, according to the present invention, such a timing design is not necessary, and it is only necessary to reflect the attribute information regarding the vertical line in the synthesis source attribute data 25, which facilitates the design of the attribute data generation circuit 16. Further, when the vertical line is to be displayed at another place, for example, the position of the dot 22, the synthesis source attribute data reflecting the attribute data regarding the vertical line is changed from 195 to 192, and the attribute data generation circuit 16 Just design. (B) Inversion: In order to perform the attribute display in which the display of the entire character is inverted as shown in FIG. 4, when the attribute data related to the inverted display is active, all the combination source attribute data 191-198 are set to "1".
The attribute data generation circuit 16 may be configured so that it becomes 1 ″.

(C) Secret: In the case of displaying an attribute such that a character is not displayed by an attribute, the composition source attribute data 1 when the attribute data relating to the secret display is active.
The attribute data generation circuit 16 may be configured so that all of 91 to 198 become "10".

(D) Underline: As shown in FIG. 5, when performing an attribute display such that an underline is superimposed on a character, the attribute data relating to the underline is active.
Further, when the raster address generated from the display address generation circuit 11 has a value indicating the bottom of the character, all the combination source attribute data 191-198 are "0".
The attribute data generating circuit 16 may be configured to have a structure of 1 ″. For that purpose, the raster address is input from the display address 11 to the attribute data generating circuit 16, and the raster address and the character are stored in the attribute data generating circuit 16. You need to compare the raster address at the bottom to determine if the raster address now has a value that indicates the bottom of the character, which was also required in the prior art to attribute underlines. Further, in order to make the underline into a dotted line as shown in Fig. 6, all the combination source attribute data 191-198 are not set to "01", but the combination source attribute data 191, 193, 195, 197 are set to "
01 "and the composition source attribute data 192, 1
94, 196, 198 may be set to "00".

[0021]

According to the present invention, when the character display data is generated, the character font data and the attribute data are combined at a plurality of bits at the same time, so that the circuit for generating the attribute data can be easily designed, and the circuit becomes more complicated. It is possible to display various attributes relatively easily, and if the number of bits of the character font data is increased, it is only necessary to increase the number of attribute synthesis circuits, which facilitates circuit design. When switching from the normal mode for displaying half-width characters of 8 dots in width to the high resolution mode of 14 dots, it is only necessary to increase the number of synthesis circuits from 8 to 14.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention.

FIG. 2 is a conceptual diagram showing a display character composed of dots of the present invention.

FIG. 3 is a conceptual diagram showing vertical line display by attribute display according to the present invention.

FIG. 4 is a conceptual diagram showing reverse display by attribute display according to the present invention.

FIG. 5 is a conceptual diagram showing underline display by attribute display according to the present invention.

FIG. 6 is a conceptual diagram showing underline display by attribute display according to the present invention.

FIG. 7 is a conceptual diagram of a character display circuit according to a conventional technique.

[Explanation of symbols]

11 ... Display address generation circuit 12 ... Character code memory 13 ... Kanji ROM 14 ... Character font data generation circuit 15 ... Attribute code memory 16 ... Attribute data generation circuit 171 to 178 ... Attribute synthesizing circuit 18 ... Parallel-serial converting circuit 191 to 198 ... Combining source attribute data 21 to 28 ... Dots forming characters 31 ... Vertical line 32 ... Dots forming characters 41. ..Character display when display attributes are not changed by attribute 42 ... Character display when reversed display by attribute 51 ... Underline by solid line 52 ... Dots forming characters 61 ... By dotted line Underline 62 ... Dots 71 that make up characters ..Character font data generation circuit 72 ... Kanji ROM 73 ... Parallel / serial conversion circuit 74 ... Attribute data generation circuit 75 ... Character font data 76 ... Combining source character font data 77 ... Combining Original attribute data

Claims (1)

[Claims] In the character display device in the information processing device, when the display data of the character is generated, the character font data and the attribute data representing the display attribute of the character are simultaneously combined in a plurality of bits, and then the display data is converted into parallel serial data. A character attribute synthesizing device in a character display device, wherein: