JPH06308932A - Character processor - Google Patents

Abstract

PURPOSE:To provide a character processor occurring no fragmentation and attaining a high speed process. CONSTITUTION:A code entry table 45 is a table making a cache character code to address, and a page entry table 46 is a table making the data registered in the code entry table 45 and the data offset 43 of 4 bits to address. Further, a real memory 47 for image register is page divided, and e. g. 1K bytes are allocated to one page. A virtual storage space associated with code information consists of the code entry table 45 and the page entry table 46, and the address of the page of the real memory 47 for image register is allocated to the virtual storage space optionally.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a character processing device,
In particular, the present invention relates to a character processing device having a method of storing image data converted from a vector font in a cache memory and using it.

[0002]

2. Description of the Related Art A conventional character processing apparatus stores bit map data expanded from a vector font in a cache memory in order to speed up the processing speed, and when the same vector font is input, the bit data is stored in the cache memory. The method of reading and using map data is often used. However, since the capacity of the cache memory is finite, when the characters registered in the cache memory become full, it is necessary to delete the bitmap data of unnecessary characters and register the new character data.

Various proposals have been made as to which character data should be deleted from the cache memory, and one of the most general methods is the LRU method. This method
This is a method of sequentially erasing the characters registered in the cache memory that have not been used for the longest time.

When characters are deleted by this deletion method, the registration area of the cache memory is fragmented (hereinafter referred to as fragmentation). When fragmentation occurs, small areas that cannot be used are generated everywhere in the cache memory. Therefore, it is necessary to relocate the unused small areas into a usable state.

[0005]

Conventionally, measures have been taken against the relocation processing, but there has been a problem that it is difficult to cause fragmentation and to enable high speed processing.

As prior art related to the present invention,
Some are disclosed in "High-quality Japanese character output method" on pages 144 to 150 of IPSJ journal Vol.31 No.1. In this method, the image registration area is divided into blocks of a certain size, and only characters having the same typeface attribute are registered in the same block. Then, when the image registration area is full, it is deleted in block units,
This is to prevent the generation of a small area equal to or smaller than the block size.

In view of the above-mentioned circumstances, an object of the present invention is to provide a character processing device which enables high speed processing without causing fragmentation.

[0008]

In order to achieve the above-mentioned object, the present invention is a character processing apparatus for expanding code information input from an external device into image data and displaying or outputting the image data, the registration of the image data. The area is configured as a plurality of pages each having a predetermined size as a unit, and the address of the page is assigned to a virtual storage space associated with the code information.

[0009]

According to the present invention, since the virtual storage space associated with the code information is used, the image data registration or deletion processing is simple and can be processed at high speed. Further, since the registration area of the image data is configured as a plurality of pages each having a predetermined size and the pages can be arbitrarily registered in the virtual storage space, the occurrence of fragmentation can be suppressed.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the drawings. FIG. 8 is a hardware configuration diagram of a system including the character processing device of the present invention. In the figure, 21 is a host computer for generating data (that is, graphic and character data) forming a document, 22 is an image expanding device for expanding the data into image data, and 28 is an output device such as a printer or a display. .

The image expansion unit 22 receives an input interface 23 for controlling communication with the host computer 21, receives graphic and character data from the input interface 23, and converts the graphic data into image data. The image data is sent to the frame buffer 25 and the character data is sent to the font generation unit 27. The image development unit 24 is used to store the sent image data. The output device 28 is used to store the data stored in the frame buffer 25.
Output interface 26 to be transferred to and the character code and character attributes (size, typeface, etc.) from the image expansion unit 24.
Of the font generation unit 27 which receives the data of (1) and generates the bit map data of the character from them.

In the above system, when the host computer 21 outputs graphic data or character code data, the input interface 23 receives and stores the data. If the data is graphic data, the graphic image data a is transferred to the frame buffer 25. When the code data is character code data, the code data b is sent to the font generation unit 27 to instruct development of image data. At this time, the font generation unit 27 determines whether or not the character is registered in the font cache. If the character is registered, the registered image data is read, and if not registered, the character is registered. Extract from vector data to image data. The character image data c generated by the font generation unit 27 is transferred to the frame buffer 25.

When the image data for one page is stored in the frame buffer 25, the output interface 26 transfers the data in the frame buffer 25 to the output device 28 to start printing.

Next, the configuration of the font generation unit 27 which is an embodiment of the present invention will be described with reference to FIG. In FIG. 1, 31 is an outline data storage unit, 32 is a font expansion unit, 33 is a font cache, and the font cache 33 is a management unit that performs operations for registering characters and deleting, for example, by an LRU algorithm. Three
3a, a registration area management unit 33b, and an image registration area 3
3c and 3c.

Next, detailed functions of the registration area management unit 33b will be described with reference to FIG. Registration management unit 33b
Is the address port 40 and the code entry table 4
5, a page entry table 46, and an image registration real memory 47. Here, the code entry table 45 and the page entry table 46 constitute a logical space, and the real memory 4 for image registration is used.
7 is a physical space. Each page in the physical space is assigned to the logical space through the conversion table (code entry table 45 and page entry table 46). As will be apparent from the description below, the logical space has its address associated with a character code.

The address port 40 has a 2-bit area for storing a data code 41, a 10-bit area for storing a cache character code 42, and a data offset 4.
It has a 4-bit area for storing 3, 44 and a 10-bit area. The cache character code 42 is shifted to the left by 14 bits by the data offsets 43 and 44 and stored in the 10-bit area. For example, the letter "A" is ASCII code 41H (hex)
Therefore, the data stored in the address port 40 is "00010000010000000000000".
It becomes "0".

Further, as shown in the figure, the code entry table 45 has a cache character code 42 as an address and has a 16-bit data registration area for each address. Then, as shown in detail in FIG. 3, a total of 10 bits of 0 to 9 bits are allocated to the area for storing the upper 10 bits of the page entry, and the 11th bit is allocated to the area for registering valid and invalid. Is 1
The 2nd to 15th bits are not used. From the above, the cache character code 42 and the address of the code entry table 45 have a correspondence relationship, and the logical space can be associated with the character code.

Next, the page entry table 46 uses the upper 10 bits of the page entry and the data offset 43 as addresses, and has a 16-bit data registration area for each address. Then, as shown in detail in FIG. 4, a total of 12 bits from 0 to 11 bits are allocated to an area for storing the upper 12 bits of the image registration real memory 47, and the 13th bit indicates valid or invalid. It is assigned to the area to be registered and the 14th and 15th bits are in an unused state. As a result, 16 data registration areas (for example, 0000) of the page entry table 46 for one cache character code 42.
~ 000f) will be allocated.

Next, the actual image registration memory 47 stores 1
It is used in units of 1 Kbyte per page, and its use / unuse is managed by the page allocation table shown in FIG. The page allocation table indicates whether each page is in use or not in use by flags 1 and 0. By searching this page allocation table, which page of the image registration real memory 47 is in use It is possible to know whether it is or is unused. In the data code, (00) indicates a page of the image registration real memory 47, and (01)
Indicates a page entry table, (10) indicates a code entry table, and (11) indicates unused.

Now, referring to FIG. 1, the image developing unit 24
If the character code b is input from, the font expansion unit 32 searches the code entry table 45 of the registration area management unit 33b and determines whether the valid / invalid column of the data storage area of the corresponding address is valid or invalid. It is determined whether the character code b is registered in the cache. If it is not registered, it is expanded into image data. The expanded image data is transferred to the frame buffer 25, and the operation of registering it in the font cache is performed.

Next, the operation of registering the character image data in the font cache 33 will be described with reference to the flowchart of FIG. First, in step S1, the font expanding unit 32 sets the data code to (1
As 0), it is checked whether or not there is a free space in the code entry table 46, and when there is no free space, the process proceeds to step S2 and an operation of deleting one character from the font cache is performed. If there is a space, the process proceeds to step S3, and the data code is set to (00) and the image registration area 33 is set.
c, that is, it is determined whether or not there is a free space in the image registration real memory 47. When there is no space, step S4
In step S2, one character is deleted from the font cache as in step S2. On the other hand, when the result at step S3 is affirmative, the process proceeds to step S5, and the address of the empty area of the page entry table 46 is set in the code entry table 45.

Next, the process proceeds to step S6, and the vacant pages in the image registration real memory 47 are registered in the page entry table 46. At this time, when the image data amount of the character to be registered is equal to a plurality of pages of the image registration real memory 47, the plurality of pages are registered in the page entry table 46. The plurality of pages need not be continuous in the image registration real memory 47 and can be arbitrarily selected. Therefore, it is possible to prevent fragmentation from occurring in the image registration actual memory 47.

In step S7, the page allocation table is updated by setting a flag, and in step S8, the image data of the font is written to the selected plural pages of the real memory 47 for image registration. Be seen.

Next, the operation of deleting characters in step S4 will be described with reference to the flowchart of FIG. The page allocation table is released in step S11, the page entry table 46 is released in step S12, and the code entry table 45 is released in step S13.

As described above, in the present embodiment, the font cache device is provided with its own area management mechanism for managing the image area, and the area for actually storing the image has an appropriate size as a unit. Since the page is composed of a plurality of pages and the page is assigned to a virtual storage space in which a storage address is associated with a character code, fragmentation does not occur and high-speed processing can be performed.

In this embodiment, 1 Kbyte is allocated to one page of the image registration real memory 47, but the present invention is not limited to this. The number of bits of the address port 40 and the code entry table 4 shown in FIG.
5. The number of bits of the page entry table 46 is only one example, and it goes without saying that the present invention is not limited to this.

[0027]

As described above, according to the present invention, since fragmentation does not occur, the storage area of the font cache can be managed without relocation (garbage collection), and the search and registration processing can be performed. Can also be done fast.

[Brief description of drawings]

FIG. 1 is a block diagram showing a schematic configuration of a font generation unit of the present invention.

FIG. 2 is a functional block diagram showing a specific configuration of a registration area management unit in FIG.

FIG. 3 is an explanatory diagram of a code entry table.

FIG. 4 is an explanatory diagram of a page entry table.

FIG. 5 is a diagram showing an example of a page allocation table.

FIG. 6 is a flowchart for explaining the operation of this embodiment.

FIG. 7 is a flowchart showing a cache character deletion operation.

FIG. 8 is a block diagram of a system to which the present invention is applied.

[Explanation of symbols]

31 ... Outline data storage unit, 32 ... Font expansion unit, 33 ... Font cache, 33a ... Management unit, 33
b ... Registration area management unit, 33c ... Image registration area, 40
... address port, 45 ... code entry table, 4
6 ... Page entry table, 47 ... Real memory for image registration.

Claims (2)

[Claims] 1. A character processing device for expanding code information input from an external device into image data and displaying or outputting the image data, wherein a registration area of the image data is formed as a plurality of pages each having a predetermined size as a unit. A character processing device, wherein an address of the page is arbitrarily assigned to a virtual storage space associated with the code information. 2. The character processing device according to claim 1, wherein the virtual storage space includes a table in which the code information is used as an address of a direct storage area, and image data is registered by referring to the table. A character processing device characterized by being able to detect the presence or absence of.