JPH0863147A - Character font processing device - Google Patents

Abstract

PURPOSE: To improve a processing performance at the time of performing the bit map display of a magnified character with respect to a screen and a printer. CONSTITUTION: A buffer 3 holds character font data read out from a CGROM 2 as they are and buffers 4, 5 hold font data in which respective dots of character font data read out from the CGROM 2 are doubled. When a command from the CPU 1 instructs the ordinary display of the font data. a selector circuit 6 makes the buffer 3 active and makes buffers 4, 5 inactive by a selector signal to output character font data held in the buffer 3. When the command from the CPU 1 instructs the magnified display of the character font data, the selector 6 makes the buffer 3 inactive and makes buffers 4, 5 active by the selector signal to output the character font of a double magnification held in buffers 4, 5.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a character font processing circuit.
The present invention relates to a process of reading CG data from a CGROM when a G (Character Generator) data is expanded into a bitmap.

[0002]

2. Description of the Related Art Conventionally, when a CPU develops CG data such as a character font into a bitmap on a screen of a terminal device, a printer or the like, the CPU temporarily holds the character font data read from the CGROM and then stores the bitmap into the bitmap. It is being deployed.

That is, as shown in FIG. 4, the character font data read from the CGROM 2 by the CPU 8 is temporarily held in the buffer 3 and then sent to the CPU 8. C
The PU 8 sends the character font data received from the buffer 3 to a frame buffer [VRAM (Video R
AM)] to a bitmap.

In a dedicated terminal device such as POS, it is often necessary to display enlarged characters on a screen or a printer.
At that time, the CPU receives the character font data read from the CGROM as it is, enlarges the character font by performing a software operation on the character font data, and outputs the enlarged character font to a screen or a printer. It is being deployed.

[0005]

In the conventional character font processing circuit described above, when displaying enlarged characters on a screen or a printer, software calculation is performed on the character fant data read from the CGROM.
This increases the burden on the PU and causes performance degradation when displaying enlarged characters on the screen or printer.

Therefore, an object of the present invention is to solve the above problems and to provide a character font processing circuit capable of improving the processing performance when displaying enlarged characters in a bitmap on a screen or a printer. is there.

[0007]

A character font processing circuit according to the present invention comprises a storage means for storing a character font, a first holding means for holding the character font read from the storage means as it is, and the storage means. Is connected to a signal line obtained by multiplying the data line from N by N (N is a positive integer) and each dot of the character font read from the storage means is N.
Second holding means for holding the doubled font data,
Control means is provided for controlling to output one of the character font held in the first holding means and the font data held in the second holding means in response to an external instruction.

In addition to the above configuration, another character font processing circuit according to the present invention comprises means for controlling the font data held in the second holding means to be written N times in the frame buffer. .

[0009]

The character font data read from the CGROM is retained as it is in the buffer in which the data lines are connected to the CGROM in a one-to-one correspondence. Also, the data line is 1 in CGROM.
The buffer connected in pair 2 holds the font data obtained by doubling each dot of the character font data read from the CGROM.

A selector circuit controls so that the font data held in these buffers is selectively output in response to a command from the CPU.

Thus, the enlargement processing of the character font can be realized only by adding the simple hardware to the conventional character font processing circuit, and the enlarged character font is displayed on the screen of the terminal device or the printer as a bitmap. In this case, the processing performance of the CPU can be improved.

[0012]

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

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention. In the figure, the character font processing circuit according to one embodiment of the present invention is composed of buffers 3 to 5 and a selector circuit (SEL) 6.

The buffer 3 holds the character font data read from the CGROM 2 as it is, and the buffers 4, 5
Holds font data in which each dot of the character font data read from the CGROM 2 is doubled.

That is, assuming that 8 × 8 dot character font data is stored in the CGROM2, the outputs D0 to D of the CGROM2 are input to the inputs I0 to I7 of the buffer 3, respectively.
7 is directly connected by a data line in a one-to-one relationship.

Further, C is applied to the inputs I0 and I1 of the buffer 4.
The output D0 of the GROM2 has CGRO at its inputs I2 and I3.
The output D1 of M2, the output D2 of the CGROM2 to the inputs I4 and I5, and the output D of the CGROM2 to the inputs I6 and I7.
3 are each connected by a data line.

Furthermore, the output D4 of the CGROM 2 is applied to the inputs I8 and I9 of the buffer 5, and the CGR is applied to the inputs I10 and I11.
Output D5 of OM2 has CGROM2 at inputs I12 and I13.
The output D6 of the CGROM2 is connected to the inputs I14 and I15 by the data line.

Therefore, each bit of the character font data of the CGROM 2 is held in the corresponding bit in the buffer 3, and each dot of the character font data of the CGROM 2 is held in each of the corresponding 2 bits in the buffers 4 and 5. . That is, the buffers 4 and 5 hold data in which each dot of the character font data of the CGROM 2 is doubled.

On the other hand, the outputs O0 to O7 of the buffer 3 are C
Inputs DB0 to DB7 of PU1 are connected by data lines. Further, the outputs O0 to O7 of the buffer 4 are connected to the inputs DB0 to DB7 of the CPU 1 by data lines, and the buffer 5
Inputs DB8 to DB15 of the CPU 1 are connected to the outputs O8 to O15 of the CPU 1 by data lines.

When the selector circuit 6 receives a command related to the enlarged display from the CPU 1, it controls the active / inactive state of the buffers 3 to 5 by the select signal 101.

Normal display and enlarged display of a character font according to an embodiment of the present invention will be described with reference to FIG.

When the character font data in the CGROM 2 is normally displayed, the CPU 1 outputs to the selector circuit 6 a command instructing normal display of the character font. When the selector circuit 6 receives the command, the selector signal 101
Activates buffer 3 and buffers 4 and 5
Deactivate.

As a result, when the CPU 1 reads the character font data from the CGROM 2, the character font data read from the CGROM 2 is temporarily held in the buffer 3 and then output from the buffer 3 to the CPU 1.

On the other hand, when the character font data in the CGROM 2 is enlarged and displayed, the CPU 1 outputs a command for instructing the enlarged display of the character font to the selector circuit 6. When the selector circuit 6 receives the command, the selector circuit 101 deactivates the buffer 3 and activates the buffers 4 and 5.

As a result, when the CPU 1 reads the character font data from the CGROM 2, each dot of the character font data read from the CGROM 2 is held as double font data in the buffers 4 and 5, respectively, and thereafter,
The data is output from the buffers 4 and 5 to the CPU 1.

That is, only by selecting the font data read from the CGROM 2 and held in the buffers 4 and 5, the character font data read from the CGROM 2 is automatically doubled.

FIG. 2 is a diagram showing horizontal and vertical enlargement processing of a character font according to an embodiment of the present invention. Figure 2
2A shows character font data of 8 × 8 dots (character font data of “A”) stored in CGROM2, and FIG. 2B shows character font data for one line read from CGROM2. 2 (c) is FIG. 2 (b)
2D shows the font data obtained by doubling the character font data in the horizontal direction, and FIG. 2D shows the font data obtained by doubling the character font data in FIG. 2A in the horizontal and vertical directions. .

FIG. 3 is a flow chart showing the vertical enlargement processing of a character font according to an embodiment of the present invention. The horizontal and vertical enlargement processing of a character font according to an embodiment of the present invention will be described with reference to FIGS. 1 to 3.

When the character font data [see FIG. 2A] of the CGROM 2 is enlarged and displayed, the CPU 1 outputs to the selector circuit 6 a command instructing the enlarged display of the character font. When the selector circuit 6 receives the command,
The buffer 3 is deactivated by the selector signal 101, and the buffers 4 and 5 are activated.

As a result, when the CPU 1 reads the character font data for one line from the CGROM 2 (steps S1 and S2 in FIG. 3) [see FIG. 2B], the character font data for one line read from the CGROM 2 is read. Each dot is held in the buffers 4 and 5 as doubled font data (step S3 in FIG. 3) [FIG.
See (c)].

When the CPU 1 receives the font data held in the buffers 4 and 5, that is, the font data which has been enlarged twice in the horizontal direction, the font data which has been enlarged twice in the horizontal direction is first stored in a VRAM (not shown). Display position 2 x L-
Write on the first line (step S4 in FIG. 3).

Subsequently, the CPU 1 writes the font data, which is doubled in the horizontal direction, on the 2 × L line at the display position of the VRAM (step S5 in FIG. 3). by this,
Each dot of the character font data for one line is doubled in the vertical direction [see FIG. 2 (d)].

The CPU 1 determines whether the processing of all the lines of the character font data has been completed, that is, whether the final line (8 lines) has been reached (step S6 in FIG. 3). If the final line has been reached, the process is executed. finish. If the final line has not been reached, the process returns to step S1 to continue the process.

As described above, the character font data stored in the CGROM 2 is held in the buffer 3 as it is, and the font data obtained by doubling each dot of the character font data is CGRO with a double data line.
Either of the character font data held in the buffers 4 and 5 held in the buffers 4 and 5 connected to the M2 and held in the buffer 3 and the font data held in the buffers 4 and 5 under the control of the selector circuit 6 according to the command from the CPU 1. By outputting one, the enlargement processing of the character font can be realized only by adding simple hardware to the conventional character font processing circuit.

Therefore, it is possible to improve the processing performance of the CPU 1 when the enlarged character font is displayed as a bitmap on the screen (not shown) of the terminal device or the printer (not shown).

Further, by writing the font data read from the buffers 4 and 5 to the display position of the VRAM twice in succession, the character font can be doubled in the vertical direction without performing software calculation. .

In the above-described configuration and its processing operation, the case where the character font is enlarged twice in the horizontal direction and the vertical direction has been described. However, N buffers (N is a positive integer) are arranged and those buffers are arranged. CGROM2 with N times the data line
It is also possible to enlarge the character font N times in the horizontal and vertical directions by connecting to.

[0038]

As described above, according to the present invention, the first holding means for holding the character font read from the storage means as it is and the data line from the storage means are multiplied by N (N is a positive integer). The data held in one of the second holding means connected to the signal line and holding the font data in which each dot of the character font read from the storage means is multiplied by N times is output in accordance with an external instruction. By controlling, it is possible to improve the processing performance when the enlarged character is displayed as a bitmap on the screen or the printer.

[Brief description of drawings]

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

2 (a) is an 8 × 8 image stored in the CGROM of FIG.
The figure which shows the character font data of the dot, (b) the figure which shows the character font data of 1 line which is read from the CGROM of Figure 1, (c) doubles the character font data of Figure 2 (b) in the horizontal direction Figure showing enlarged font data,
2D is a diagram showing font data obtained by enlarging the character font data of FIG. 2A by 2 times in the horizontal and vertical directions.

FIG. 3 is a flow chart showing vertical enlargement processing of a character font according to an embodiment of the present invention.

FIG. 4 is a block diagram showing a configuration of a conventional example.

[Explanation of symbols]

 1 CPU 2 CGROM 3-5 buffer 6 select circuit

Claims (3)

[Claims] 1. A storage means for storing a character font, a first holding means for holding the character font read from the storage means as it is, and a data line from the storage means multiplied by N (N is a positive integer). ), Each dot of the character font read from the storage means is N
Second holding means for holding the doubled font data,
It has a control means for controlling so as to output one of the character font held in the first holding means and the font data held in the second holding means in response to an external instruction. Character font processing circuit. 2. The character font processing circuit according to claim 1, further comprising means for controlling to write the font data held in said second holding means N times in a frame buffer. 3. The control means reads the character font held in the first holding means when the character font is used as it is, and stores the read character font in the second holding means when the enlarged character of the character font is used. The character font processing circuit according to claim 1 or 2, wherein the character font processing circuit is configured to read the held font data.