JPH0365988A - Word cache system - Google Patents

Abstract

PURPOSE:To speed up display speed by providing a cache memory stored temporarily with a character string read out of a font memory in word units and a page memory which inputs a character string from a word processing part and generates display screen data. CONSTITUTION:A CPU 3 is provided with the cache memory 2 which reads a character font out of the font memory 1 according to input code information and generates a character string. Further, the system is provided with a memory 4 which is used as the working area of the CPU 3 and the page memory 5 where the character string generated by the CPU 3 is written. Thus, when a character string corresponding to a work is registered in the cache memory 2, the CPU 3 reads the character string corresponding to the word out of the cache memory 2. Consequently, a processing time can be shortened greatly and the display speed is therefore made high speed.

Description

DETAILED DESCRIPTION OF THE INVENTION <Field of Industrial Application> The present invention relates to a word cache system used in word processors, computer systems, and the like.

<Prior Art> As a character output device used in word processors, computer systems, etc., a font cache type character output device shown in FIG. 6 is conventionally known.

The character output device shown in this figure includes a font memory +01 in which a large number of character fonts are stored, and a CPU 1 that reads character fonts from the font memory +01 based on manually input code information and creates a character string.
03, and a cache memory 102 provided in this CPU 103.

a memory 104 used as a work area for the CPU l 03; and a page memory 105 into which the character string created by the CP[J l 03 is written.
It is equipped with

When the code information is input, the cache memory 102 and the fosito memory 10 are
1 to create a character string, and
This is written into the page memory +05 and displayed on a display such as a CRT.

In this case, the CPU 103 accesses the cache memory 102 and font memory 101 to create a character string in the following procedure.

First, the CPU 103 reads code information for one character from the input code information as shown in FIG. 7 (step 5TIO+), and the character to be displayed is registered in the cache memory 102 based on this code information. If it is not registered, the font memory 101 is accessed and the character font of the character to be displayed is read out (step 5T103).

Next, the CPIJ 103 develops the character font on a bitmap formed on the memory 104 (step 5TI04) and registers the character font in the cache memory 102 (step 5T105).

Further, if the character font of the character to be displayed in the above process is registered in the cache memory 102, the CPU 103 directly takes out the character font from the cache memory 102 and develops it on the bitmap.

After that, as shown in FIG. 8, the CPU 103 performs processing to mask the bits outside the character boundaries for characters whose byte boundaries and character boundaries do not match, and also calculates the address on the page memory +05 to set the character font. is written on the page memory (step 5T103.5T10
7).

Address calculation in this case is performed by incrementing in the X direction of the display screen 110 as shown in FIG.

In this way, in this character output device, the processing speed is improved by using the cache memory 102 to reduce the processing to access the font memory I01, the processing to develop into a pit map, etc.

However, in such a font cache type character output device, it is necessary to perform various processes such as reading the character font for each character, processing to adapt to byte boundaries, and address calculation processing due to discontinuity of transfer destination addresses. Therefore, there was a problem that the processing took too much time.

<Object of the Invention> In view of the above circumstances, an object of the present invention is to provide a word cache system that can significantly shorten processing time and thereby increase display speed.

<Structure of the Invention> In order to solve the above problems, the word cache system according to the present invention temporarily stores a font memory in which a single character font is stored and character strings read from this font memory in units of words. When the character string to be created is stored in the cache memory word by word, the character font is read from the cache memory word by word to create a character string, and the character string to be created is a word. a word processing section that reads characters from the font memory in units of characters and creates a character string when the characters are not stored in the cache memory in units; and a word processing section that takes in the character strings created by the word processing section to create display screen data. It is characterized by having a page memory.

Hereinafter, the present invention will be specifically explained based on one embodiment.

FIG. 1 is a block diagram showing one embodiment of a word cache system according to the present invention.

The word cache system shown in this figure is a font memory that stores many character fonts! and a CPL that reads a character font from the font memory l based on manually input code information and creates a character string.
I3 and cache memory 2 provided in this CPU3
, a memory 4 used as a work area for the CPU 3, and a page memory 5 into which character strings created by the CPU 3 are written.

When code information is input, the cache memory 2 and font memory 1 are accessed according to this code information to create a character string, and this is written to the page memory 5 and displayed on a display such as a CRT. do.

In this case, the CPU 3 accesses the cache memory 2 and font memory 1 to create a character string in the following procedure.

First, as shown in FIG. 2, the CPU 3 first extracts delimiters such as "," and spaces from the input code information and divides the code information into words.
■Read code information for words (Step 5TI),
Based on this code information, it is checked whether the word to be displayed is registered in the cache memory 2 (step 5T2).

After this, if the word is not registered in the cache memory 2, the CPU 3 accesses the cache memory 2 again and checks whether the character font of each character constituting the word is registered (step 5T2.5T4).

If the first character among these characters is not registered in the cache memory 2, the CPU 3 accesses the font memory l and reads out the character font of this character (step 5T5), The character font is developed on the bitmap (step 5T6).

Thereafter, the CPU 3 registers the ITiI character font in the cache memory 2 (step 5T7).

In addition, in the above-described process (step 5T4), if the first character constituting the word is registered in the cache memory 2, the CPU 3 directly reads this character font from the cache memory 2, and reads and expands the character font described above. The processing, expansion into a bitmap, and registration into the cache memory 2 are skipped.

Next, the CPU 3 checks whether the character boundaries and byte boundaries of this character font match. If they do not match, the CPU 3 performs processing to mask the bits outside the character boundaries, and then writes the characters in the page memory 5. The address calculation is performed and the character font is written onto the page memory 5 (steps 5T2 and 5T9).

Thereafter, the CPU 3 executes the above-described processing for each of the remaining characters constituting the word, writes the character font corresponding to each of these characters into the page memory 5, and displays it on a display such as a CRT.

When the processing for one word is completed, the CPU 3 registers the character string obtained by the above-described processing in the cache memory 2 in word units, and ends the processing for this word.

Further, in the above-described process, if a character string corresponding to the word is registered in the cache memory 2, the CPU 3 reads the character string corresponding to this word from the cache memory 2.

After this, the CPU 3 performs processing to mask bits outside the character boundaries so that the character boundaries and byte boundaries of this character string match, and also calculates the address on the page memory 5 and writes it to the page memory. CR at
The word is displayed on a display such as T, and the processing for this word is completed (steps 5TIO, 5TII).

In this embodiment, the cache memory 2
Since character strings are registered in units of words, as shown in Figure 3, once a single word separated by "," or a space, such as the word "the", is read out from the font memory l, this when you need it again.

The character string corresponding to this word can be read all at once from the cache memory 2, and written onto the page memory 5 by performing byte boundary processing and address calculation processing - times.

In this case, the word "the" is composed of three characters as shown in Figure 4, so in the conventional font cache method, each character "t" and "h-e" that make up the- is Processing such as reading character strings, adapting to byte boundaries, and calculating addresses due to discontinuity of transfer destination addresses has been replaced with processing of adapting to byte boundaries and address calculations due to discontinuity of transfer destination addresses. The character string "-the" can be written onto the page memory 5 by performing the process only once.

This can significantly reduce processing time.
Display speed can be increased.

Furthermore, in the embodiment described above, character strings are registered in the cache memory 2 in units of words, but even if character strings are registered in units of phrases as shown in FIG. A similar effect can be obtained.

Effects> As explained above, according to the present invention, the processing time can be significantly shortened, and thereby the display speed can be increased.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of the word cache system according to the present invention, FIG. 2 is a flowchart showing an example of word processing in the word cache system shown in FIG. 1, and FIG. 3 is a word cache shown in FIG. 1. A schematic diagram for explaining an example of the operation of the system, FIG. 4 is a schematic diagram for explaining an example of the operation of the word cache system shown in FIG. 1, and FIG. 5 is another embodiment of the word cache system according to the present invention. FIG. 6 is a block diagram showing an example of a conventionally known character output device, FIG. 7 is a flowchart showing an example of character processing by the character output device shown in FIG. 6, and FIG. 9 is a schematic diagram for explaining an example of the operation of the character output device shown in FIG. 6, and FIG. 9 is a schematic diagram for explaining an example of the operation of the character output device shown in FIG. ■-Font memory, 2-Cache memory, 3--Word processing unit (CPU), 5--Page memory Applicant Ricoh Co., Ltd. Figure 4 bit Figure 5

Claims (1)

[Claims] (1) A font memory that stores character fonts, a cache memory that temporarily stores character strings read from this font memory in units of words, and a character string to be created is stored in the cache memory in units of words. reads the character font in units of words from the cache memory to create a character string;
a word processing unit that reads characters from the font memory in units of characters and creates a character string when the character string to be created is not stored in the cache memory in units of words; A word cache system comprising a page memory for importing and creating display screen data.