JPH04163595A - Method of letter drawing process - Google Patents

Abstract

PURPOSE:To reduce overhead so as to carry out display without stopping a following moving picture by taking a letter code in from a code buffer based on the address taken in from an address information FIFO buffer. CONSTITUTION:While a letter code to be displayed by an application program 1-1 operated on a CPU 1 is written into a code buffer 2, the address of the letter code is stored in an address information FIFO buffer 3, and the existence of data is set in an information register 4 for data existing. When the setting of the information register 4 for data existing is detected by a CPU 5, the letter code is taken in from the code buffer based on the address taken in from the address information FIFO buffer 3. By developing the letter code in order on a bitmap data, it is written into a frame memory 8 for bitmap type display, and the letter is displayed on a screen 9. Overhead is reduced, and display is carried out without stopping a following action.

Description

[Detailed Description of the Invention] [Summary] Regarding a character drawing processing method for drawing characters, when an application program attempts to display a character code by writing it into a code buffer, the next operation is not interrupted and the overhead is reduced. There is an application program that runs on a certain CPU, performs various business processes, writes the character code to the code buffer when displaying characters, and continues the next process. a data presence notification register that sets the presence of a character code in response to writing the character code into the code buffer; and an address notification FIFO buffer that stores the address of the character code;
Other C
When detected by the PU, the character code is read from the code buffer based on the address read from the address notification FIF○Huffa, and the read character code is sequentially developed into bitmap data and written to the frame memory for focus map display. , configure the characters to be displayed on the screen.

[Industrial application field]

The present invention relates to a character drawing processing method for drawing characters. Generally, it is desired to display text and graph data quickly and without processing delay (characters and graph data) on a display device based on data in code format or bitmap format.

[Prior art and problems to be solved by the invention] Conventionally, when an application program running on a certain CPU displays characters on a display, the application program handles the characters as code data, and in order to display this, the application program treats the characters as code data. Then, this code data is expanded onto the bitmap memory. Then, a serial video signal is read out from this bitmap memory and displayed on the display. At this time, when the application program writes the code data to be displayed by the running CPU into the code buffer, and when the program running on the same CPU extracts the code data from this code buffer and expands it onto the bitmap memory, Every time an application program writes code data to the code buffer, processing to expand the code data extracted from it and expand it to the focus map memory occurs, and the processing time is much longer than the time to write the code data to the code buffer. This poses a problem in that a large amount of time is required for the process, the overhead of the CPU increases, and the processing by the application program is interrupted.

An object of the present invention is to reduce overhead when an application program attempts to display a character code by writing it into a code buffer without interrupting the next operation.

[Means to solve the problem]

Means for solving the problem will be explained with reference to FIG.

In FIG. 1, a code buffer 2 is a buffer into which an application program 1-1 running on a certain CPUI requests display by writing a character code.

Address notification FIFO buffer 3 is code buffer 2
This is a buffer that stores the address of data written to.

The data presence notification register 4 is a register that stores information indicating that a character code is present in the code buffer 2.

The CPU 5 is another CPU, and when it detects that data presence is set in the data presence notification register 4, it reads a character code from the code buffer 2 based on the address fetched from the address notification FIF○ buffer 3. The data is taken in and expanded into the frame memory 8 for bitmap type display.

[Effect]

As shown in FIG. 1, the present invention writes the address of the character code in response to the application program l-1 running on a certain CPU writing the character code to be displayed in the code 7 area 2. Address notification FI
The FO is stored in the huff sofa 3 and the presence of data is set in the data presence notification register 4, and when the other CPU 5 detects the setting of this data presence notification register 4, it uses the address fetched from the address notification FIFO buffer 3. The character code is read from the code buffer 2, and this character code is sequentially developed into bitmap data and written into the frame memory 8 for focus map type display, and the characters are transferred to the screen 9.
I'm trying to display it at the top.

Therefore, when the application program 1-1 running on the CPLI1 writes a character code to the code no\/nofa 2, the next operation is not interrupted, and it is possible to reduce the number of characters and quickly display the character code.

〔Example〕

Next, the configuration and operation of one embodiment of the present invention will be explained in detail using FIGS. 1 and 2.

In the first article, the CPUI is a CPIJ (central processing unit) that performs various business processes based on the application program 1-1 loaded into the memory, and is installed on a hardware device.

The code buffer 2 is a buffer for the application program 1-1 running on the CPUI to request display by writing a character code.

Address notification FIFO buffer 3 is code buffer 2
This is a FIFO buffer for storing the address of data written to and for notifying the address.

The data presence notification register 4 is a register that sets data presence when a character code is written to the code buffer 2 and notifies that data is present.

The CPU 5 is another CPU provided separately from the CPU on the hardware device, and performs processing based on the hardware control section 6 and pattern expansion section 7, which are programs.

The hardware control section 6 polls at regular intervals and when detecting that data presence is set in the data presence notification register 4, activates the pattern development section 7 and gives a drawing instruction.

Based on the notification from the hardware control unit 6, the pattern expansion unit 7 stores the character code of the address fetched from the address notification FIFO buffer 3 in the code buffer 2.
The image data is taken in from the computer, expanded, converted into a bitmap, and written into the frame memory 8 for dot map display. By this writing, characters are displayed on the screen 9 on the display using the video signal read out from the dot map type display frame memory 8.

Next, the operation of the configuration shown in FIG. 1 will be explained in detail using the flowchart shown in FIG.

A character drawing request is generated in the application program 1-1 running on the fIICPLJI, and the character code of the character to be displayed is written into the code buffer 2 ((2), (2) in FIG. 2).

+21 (1) Application program 1-1
In response to writing the character code to code buffer 2, the hardware (or CPU) sets data presence to the data presence notification register 4 and sends an address notification F of the address of the data written to code buffer 2.
Set it in IFO buffer 3 (Fig. 2, ■, 0).

+31 Data presence notification register 4 indicates data presence with F21
In response to the setting, when the hardware control section 6 polls at regular intervals and detects the presence of data (2nd jump: YES), it instructs the pattern development section 5 to develop the pattern.

+4) The pattern expansion unit 7, which is instructed to expand the pattern at +31, takes in all the addresses from the address notification FIFO buffer 3 into the internal memory, converts the character code read from the code buffer 2 into a bitmap using this address, and displays it in a dot map format. frame memory 8
(Fig. 2 [phase], O).

(51+41 is frame memory 8 for dot map display)
The dot data written on the screen is read out serially to generate a video signal, and characters are displayed on the screen 9 of the display.

As described above, the application 1-1 running on CPLII can write the character code to be displayed into the code buffer 2 and immediately continue the next process.
During this time, a separately provided CPU 5 polls at regular intervals to take out the character code from the code buffer 2, convert it into a bitmap, write it into the dot map type display frame memory 8, and display the characters on the screen 9.

As a result, the application programs 1 to 1 installed in the hardware device and running on the CPU 1 can immediately shift to the next process when displaying characters without being interrupted by the expansion of character codes. At the same time, it becomes possible to quickly display characters.

FIG. 2 shows a flowchart explaining the operation of the present invention.

The CPUI application is an application program running on the CPU 1 in FIG. 1, and writes a character code to the code buffer 2 in response to a character drawing processing request (■, ■).

The hardware device shown in FIG. 1 is a hardware device that runs an application program 1 running on the CPUI.
-1 is the hardware device. This hardware device, in response to the fact that the application program 1-1 running on the CPUI writes the character code to be displayed to the code buffer 2 at (■), sets data to the notification register to indicate that data is present at 0. The address of the character code written in the code buffer 2 in and ■ is set in the address notification FIF○ buffer 3.

The CPU 5 shown in FIG. 1 corresponds to setting the presence of data in the data presence notification register 4 with 0, by polling at regular intervals and setting the presence of data in the data presence notification register 4. If it is detected that there is an address (character code) in the address notification FIFO buffer 3 (in the case of ``YES''), the data (character code) of the address in the address notification FIFO buffer 3 is taken in from the code buffer. Then, in step O, the captured character code is converted into a bitmap and written into the dot map type display frame memory 8, and the character code is expanded. As a result, characters are displayed on the screen 9 on the display using the video signal serially read out from the dontomasop type display frame memory 8.

〔Effect of the invention〕

As explained above, according to the present invention, the CPU on which the application program 1-1 operates only needs to write character codes to the code buffer 2, and other CPUs
5 takes in this character code, converts it into a map, writes it to the dot map type display frame memory 8, and displays the character on the screen 9. Therefore, the CPU on which the application program 1-1 runs is a dot map type display frame memory 8. Normal processing can be continued without interrupting the process due to changes, and overflow can be reduced.

[Brief explanation of drawings]

Figure 1 is a configuration diagram of one embodiment of the present invention. FIG. 2 shows a flowchart explaining the operation of the present invention. In the diagram, 1.5: CPU 1-1 = Application program 2: Code buffer 3 Near address notification FIFO buffer 4: Data notification register 6: Hardware control section 7: Pattern development section 8: Frame memory for dot map display 9: Screen

Claims (1)

[Claims] In a character drawing processing method for drawing characters, a certain CPU
(1) An application program (1-1) that operates on the above to perform various business processes, writes character codes to the code buffer (2) when displaying characters, and continues the next process; ) writes a character code to the code buffer (2), a data presence notification register (4) sets the presence of a character code, and an address notification FIFO buffer (3) stores the address of the character code. When the other CPU (5) detects that this data presence notification register (4) is set, the address notification FI
Based on the address read from the FO buffer (3), character codes are read from the code buffer (2), and the read character codes are sequentially developed into bitmap data and written to the bitmap type display frame memory (8). , a character drawing processing method characterized in that the character is configured to be displayed on a screen (9).