JPS6341894A - Access system for character generator - Google Patents

Abstract

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

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a method for creating character patterns in a display device or a printing device, and particularly to a display device or a printing device that can use a plurality of character encoding systems. This article relates to a character generator access method in .

[Conventional technology]

The JIS Kanji code system was revised in 1983,
Although it has begun to be applied to various products, the old code system of the 1978 version is also used in existing systems, and
There are some differences from the new code above. In order to use such multiple code systems in the same system, for example, the method described in Japanese Unexamined Patent Publication No. 56-90339 uses a writable random access character generator (CG) as a character generator (hereinafter abbreviated as CG).・Memory (hereinafter abbreviated as RAM) is used to change the character font pattern in the CG as necessary.

However, in such a method, no consideration is given to the case where a read-only memory (hereinafter abbreviated as ROM) is used as the CG.

[Problem that the invention seeks to solve]

Recently, CG requires a large amount of memory, so large-capacity ROMs with specific character font patterns written in advance are often used as CGs, but in the conventional technology, when ROMs are used No consideration was given to changing the character pattern.

An object of the present invention is to improve such problems and provide access to a character generator that can create display data or print data for character codes of a plurality of character encoding systems in a display device or a printing device using a ROM. The goal is to provide a method.

Means for Solving Problem C] To achieve the above object, the access method of the character generator of the present invention creates a CG address from a CG that stores character font patterns and a given character code. A display device or a printing device having a conversion circuit for converting an address is characterized in that the parameters for the address conversion are rewritten in accordance with a change in character code.

[Effect]

When reading a character font pattern from a CG using a character hood given by a program, the character code is converted to a CG address based on specific conversion information, and the
G, and its font pattern is read out. By making the address conversion memory that stores conversion information for creating a CG address from this character code rewritable, it is possible to process character codes of a plurality of character code systems using the same CG.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a configuration diagram of a printer control device in one embodiment of the present invention.

The printer control device of this embodiment includes a microprocessor l.
, control memory 2. Data buffer 32 character code register 4. Memory for address conversion 5. ROM for CG
6. Output buffer7. Printer control unit 8. Printer interface section 9° and host device interface section 1
Consists of o.

The control memory 2 stores a control program for the microprocessor 1, the data buffer 3 holds data such as character codes, and the character codes are set in the character code register 4.

In addition, the address conversion memory 5 converts this character code into C
Convert to G ROM address.

FIG. 4 is a brooch showing the font pattern output of the printer control device in one embodiment of the present invention! - (see Figure 1).

When the microprocessor 1 receives a printing start from the host device 112 (400), the microprocessor 1 reads the system memory 1 via the system bus 14° and the host device interface 10.
The receiver takes the character code prepared in 3 and writes it to data buffer 3 (401).

Next, the character code is read from the data buffer 3 and set in the character code register 4 (402). The character code register 4 outputs the character code register output signal A to the address conversion memory 5 according to the character code (403), and the address conversion memory 5 outputs this signal A to the CG ROM address of the CG R○M6. Convert signal B to C (JROM64: send (404).R for CG
The OM6 outputs the phant pattern to the microprocessor bus 15 according to the address signal B (405),
The font pattern is output by the output puff 77 under the control of the printer control section 8. and is output to the printer 11 and printed via the printer interface section 9 (4
06).

FIG. 2 is a format diagram of the table conversion command in the present invention (see FIG. 1).

The table conversion command 21 of this embodiment is a command activated by the upper bag M12 to the print control device when changing the character code system.

Consists of command code, table number, and table data start address.

This table number is assigned to each character code system used, and the table data start address indicates the start address of character:ID/CG address conversion data stored in the system memory 13.

FIG. 3 is a side view of the configuration of the data buffer according to the present invention (see FIG. 1).

The data buffer 3 of this embodiment consists of a character code storage area, a registered table number storage area, and various parameter storage areas. In the character code storage area,
Character codes corresponding to font patterns are stored, and table numbers assigned to each usable character code system are stored in the registered table number storage area. In addition, various parameter storage areas include CG RO
Parameters for performing address translation of M are stored.

FIG. 5 is a flowchart of changing the character code system of the printer control device in one embodiment of the present invention (see FIGS. 1 to 3).

When the microprocessor l receives the table conversion command 21 from the host device 12 (500), it reads the table number registered in the registered table number area of the data buffer 3 and the table number specified by the table conversion command 21. (501).

If these table numbers match (502), the command operation ends (503).

If they do not match (502), the contents of the system memory 13 indicated by the table data start address of the table data conversion command 21 are transferred to the system bus 14. Then, it is registered in the address conversion memory 5 via the host device interface unit 1° (504).

When the table data registration is completed in this way, the microprocessor 1 updates the contents of the registered table number storage area of the data buffer 3 (505).

〔Effect of the invention〕

As explained above, according to the present invention, since it is possible to change the font pattern corresponding to a single character code, programs for multiple character code systems can be used in display devices or printing devices that use large-capacity ROM as CG. can be used.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a printer control device according to an embodiment of the present invention, FIG. 2 is a format diagram of a table conversion command according to the present invention, FIG. 3 is a side view of the configuration of a data buffer according to the present invention, and FIG. FIG. 5 is a flowchart showing the font pattern output of the printer control device in one embodiment of the present invention. FIG. 5 is a flowchart of changing the character code system of the printer control device in one embodiment of the present invention. 1: Microprocessor, 2: Control memory, 3
: data buffer, 4: character code register, 5 memory for near address conversion, 6: CG ROM, 7: output puffer, 8: printer control section. 9: Printer interface section, 1o: Upper device interface section, 11: Printer, 12: Upper device, 13
System memory, 14 System bus, 15: Microprocessor bus, 21: Table conversion command, A:
Character code register output signal, B: CG ROM address signal. Figure 1 Figure 2 Figure 3 Figure 4 Print control device

Claims (1)

[Claims] 1. A display device or a printing device equipped with a character generator that stores character font patterns, and a conversion circuit for creating an address for the character font pattern in the character generator from a character code given from a host device. An access method for a character generator characterized in that the parameter for the address conversion is rewritten according to the change in the character encoding system.