JPS6332194B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a terminal device etc. that receives a character code and displays or prints a character pattern corresponding to the received character code. Concerning character code conversion method for conversion.

The following explanation uses the Kanji code specified in JISC-6226 "Kanji code system for information exchange" as an example of the character code.

Conventionally, terminal devices and the like that process the above-mentioned Kanji codes have adopted a method of converting Kanji codes into character generator (abbreviated as CG) addresses by referring to a code conversion memory. Two typical examples of such character code conversion methods will be briefly explained with reference to FIGS. 1 and 2.

The method shown in Fig. 1 uses memory 2 and 3 for code conversion.
is used. Kanji codes are stored in memory 2 in order starting from address 0, and memory 3
The CG addresses for the kanji codes in the corresponding addresses of the memory 2 are stored in order from address 0. Register 4 the kanji code to be converted.
Then, while incrementing address counter 1 from zero, the contents of each address in memories 2 and 3 are sequentially read into registers 6 and 7. Comparison circuit 5 compares the Kanji code read into register 6 and the Kanji code in register 4, and outputs a match signal 8 when a match is found. When this match signal 8 is output, the contents of register 7, that is, the target CG
Sends the address and also resets address counter 1. Address counter 1 is memory 2, 3
If the match signal 8 is not output even after counting up to the final address, the Kanji code in question is a so-called non-registered character that has not been registered in the CG, and non-standard character processing is performed. In other words, processes such as displaying a specific character pattern on the display screen, sending the Kanji code of the external character to the center, and importing the corresponding character pattern, are performed.

The method described above has the advantage that it does not require a very large capacity memory for code conversion, but has the disadvantage that the conversion speed is naturally limited because the memory is referenced many times.

In the method shown in FIG. 2, the code conversion memory 10 is accessed by directly specifying an address using a Kanji code. That is, when the Kanji code to be converted is set in the address register 9, the corresponding CG address is read into the register 11 from the address designated by the Kanji code in the memory 10. CG
Regarding kanji codes (external characters) for character patterns that have not been registered, undefined codes are read from the memory 10. In this case, the external character processing described above is performed.

This method allows code conversion with one memory access, so the conversion speed is fast. But memory 10
Since it is necessary to allocate one address to a non-standard character, a memory capacity of 65K words is required to convert a 2-byte kanji code, which poses a cost problem.

Therefore, an object of the present invention is to provide a high-speed and low-cost character code conversion method.

However, the basic feature of the character code conversion method according to the present invention is to determine in advance which area (described later) in the code space the character code belongs to, and to convert the character code into a conventional code conversion method according to the result. There may be a choice between converting using memory or converting according to a certain arithmetic expression.

The present invention will be specifically described below with reference to the drawings.

The 2-byte kanji code system mentioned above is the third
It can be expressed in the character code space shown in the figure. The vertical axis is the first byte (7 bits) of the Kanji code, and the horizontal axis is the second byte (7 bits).

1st byte (N) ₁₆ is (21) ₁₆ ~ (2F) ₁₆ is 2nd byte (M) ₁₆ is (21) ₁₆ ~ (7E) Area A3 of ₁₆ contains defined codes and undefined codes. This is an area where the rules are mixed. (N) ₁₆ = (30) ₁₆ ~ (73) ₁₆ ,
(M) ₁₆ = (21) ₁₆ to (7E) Area A2 of ₁₆ is an area where defined codes are arranged with regularity. (N) ₁₆ = (74) ₁₆ ~ (7F) ₁₆ , (M) ₁₆ = (21
) ₁₆
~(7E) ₁₆ area A1, and area A1 above,
Area A0 excluding A2 and A3 is an area of undefined codes.

According to the present invention, the CG address of the kanji code belonging to the definition area A2 is obtained by calculation,
For kanji codes belonging to the defined/undefined mixed area A3, the CG address is obtained using the code conversion memory.

FIG. 4 is a block diagram showing one embodiment of the present invention, and FIG. 5 is a processing flow diagram thereof.

The kanji code supplied from a processing device or the like through a data line 20 is once latched in a register 21. The determination circuit 22 compares the register 21 with a constant as shown in the processing flow diagram of FIG.
It is determined at high speed to which area A0 to A3 the kanji code within belongs to, and if it belongs to undefined areas A0 or A1, a signal is output to the signal line 33. If it is determined that it belongs to the defined area A2, a signal is output to the signal line 23. Further, if it is determined that the area belongs to the defined/undefined area A3, a signal is output to the signal line 24.

When a signal is output to the signal line 23, the kanji code in the register 21 is taken into the arithmetic circuit 25. The arithmetic circuit 25 executes a certain arithmetic expression to obtain the address of the CG 29 and sets it in the address register 27. CG29 has a built-in character pattern for the kanji code belonging to definition area A2, and the registration order is in ascending order of the code that is a combination of the first byte (N) ₁₆ and the second byte (M) ₁₆ of the kanji code. There is. Therefore, the above calculation is performed according to the calculation formula (1) such that the smallest number of the code obtained by combining the first byte and the second byte is zero.

CG address = {(N) ₁₆ - (30) ₁₆ } × (5E) ₁₆ + (M) ₁₆ ... (1) Equation CG 29 is read with the CG address determined by the arithmetic circuit 25 and set in the address register 27. The obtained character pattern is OR circuit 31
It is output to the output line 32 via.

On the other hand, when a signal is output from the determination circuit 22 to the signal line 24, the kanji code in the register 21 is compressed to 10 bits and input to the code conversion circuit 26 (the upper 3 bits of the first byte are discarded). ).
The code conversion circuit 26 may be of a memory referencing type, for example, the memory sequential search type shown in FIG. 1 or the memory direct access type using Kanji codes shown in FIG. 2, so no specific example will be shown. The CG address obtained by the code conversion circuit 26 is set in the address register 28 of the CG 30. CG address in address register 28
A character pattern is read from the CG 30 and output to the output line 32 via the OR circuit 31.

Incidentally, since the code conversion circuit 26 handles the Kanji codes in the defined/undefined mixed area A3, the Kanji codes may be determined as undefined codes. In that case, the above-mentioned general external character processing will be performed on the corresponding Kanji code. For example, if the code conversion circuit 26 has the configuration shown in FIG. All you have to do is OR it with the signal line 33. Further, when the code conversion circuit 26 has the configuration shown in FIG.
(FIG. 1) and the address counter 1 (FIG. 1), an undefined code detection signal may be created and ORed with the signal line 33 of the determination circuit 22.

To add more here, the code conversion circuit 26
handles only the kanji codes in the defined/undefined area A3, so even if the configuration shown in Figure 1 or 2 is adopted, the number of memory accesses and memory capacity required will be greatly reduced, so the code conversion speed and Cost is not really an issue.

As described in detail above, in the present invention, prior to code conversion, it is determined to which area in the character code space the character code belongs by comparing the character code with, for example, a constant;
To avoid unnecessary code conversion operations for character codes belonging to an undefined area. Furthermore, for character codes belonging to a defined area in which defined codes are regularly arranged, high-speed code conversion is performed by simple calculations. Then, code conversion using the code conversion memory is performed only for character codes belonging to the defined/undefined mixed area. Therefore, code conversion can be speeded up as a whole,
Furthermore, since the memory capacity for code conversion can be significantly reduced, cost improvements can also be achieved.

[Brief explanation of the drawing]

Figures 1 and 2 are block diagrams of conventional character code conversion methods, and Figure 3 is JISC-6226.
Figure 4 is a block diagram showing an embodiment of the present invention, Figure 5 is a diagram showing the system of kanji codes defined in
The figure is a processing flow diagram of the same embodiment. 21... Kanji code, register, 22... Judgment circuit, 25... Arithmetic circuit, 26... Code conversion circuit, 2
7, 28... Address register, 29, 30... Character generator (CG), 31... OR circuit.

Claims (1)

[Claims] 1. In an apparatus having a character pattern generator that generates a character pattern corresponding to a character code, a first character code group corresponding to a character pattern regularly arranged and registered in the character pattern generator, and the character pattern a second character code group in which character codes corresponding to character patterns registered in the generator and character patterns not registered are mixed irregularly;
means for determining a third character code group corresponding to a character pattern not registered in the character pattern generator; and determining that the character code with the determination means belongs to the first character code group. Accordingly, code conversion is performed by executing a predetermined arithmetic expression to generate a character pattern from the character pattern generator, and the code conversion memory is referred to in response to determining that the character pattern belongs to the second character code group. In response to determining that the character pattern belongs to the third character code group, A character code conversion method characterized by having means for generating a character pattern by processing non-standard characters.