JPS5941122B2 - Inch/millimeter data conversion method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an inch-millimeter data conversion method that allows data conversion between inch unit data and millimeter data to be easily performed.

[When converting numerical data x in units of Iml (mm) to numerical data in units of inches, since 1 inch = 2.54 stiffness, a multiplication of X x 2.54 is performed. Conversely, when converting numerical data X in units of inches to numerical data in m units, 1 mm - inch and a half 0.3937 inches 2.
54, so X÷2.54 or XX0.3
The calculation 937 is performed.

Therefore, in a system that requires a numerical value conversion function from inches to millimeters and a numerical value conversion function from millimeters to inches, an arithmetic circuit or processing procedure D for multiplying by 2.54 and 2. An arithmetic circuit or processing procedure E for dividing by 54 is required.

However, these multiplier circuits have very complicated circuit configurations, and as the number of digits of the multiplier increases, the circuit configuration becomes even more complicated.

Further, even when these multiplication operations are accomplished by a program such as a computer, the number of processing steps is large, and as the number of digits of the multiplier increases, the number of processing steps increases even more significantly. The present invention has been made in view of the above points, and is capable of easily converting data from inches to millimeters or from millimeters to inches.
The purpose is to provide a data conversion method.

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 2 shows a first embodiment of the present invention, in which A is an arithmetic means (first arithmetic means) for multiplying input data by 2.
, B is an arithmetic means (
C is a calculation means (third calculation means) for multiplying input data by 127.

The multiplier when converting numbers from inches to millimeters is 2.5
4, but if we express it using significant figures excluding the decimal point, the multiplier 254 excluding the decimal point is 2×1
It is factorized into 27.

On the other hand, the multiplier when converting a value from millimeters to inches is 1/2.54 + 0.3937, but if we similarly express it using significant figures, excluding the decimal point, we get a multiplier of 3937, excluding the decimal point. is factorized into 31×127. Processing of the decimal point position is easy and is not related to the gist of the present invention, so in order to simplify the explanation, it has been omitted as described above.

As mentioned above, to convert numerical data X in inches to numerical data in millimeters, ignoring the decimal point,
It is sufficient to perform a multiplication of x2x127. On the other hand, in order to convert numerical data X in millimeters to numerical data in units of inches, ignoring the decimal point, it is sufficient to perform a multiplication of x2x127.

Here, since the second multiplier 127 is common, it can be made common as shown in FIG.

In FIG. 2, when converting from inches to millimeters, first multiply by 2 using calculation means A to obtain 2X,
Next, the calculation means C multiplies 127 to 2XX127.
=254X can be obtained.

On the other hand, when converting from millimeters to inches, first multiply by 31 using calculation means B to obtain 31X, then,
Multiply by 127 by calculation means C to obtain 31XX127=3
937X can be obtained.

Multiplication circuits based on digital circuits become extremely complex as the number of digits of the multiplicand and multiplier increases. Also, when performing multiplication processing using a program on a computer, etc., when the number of digits of the multiplicand and multiplier increases,
The number of processing steps increases significantly and the use of storage registers becomes cumbersome.

For example, the result obtained by multiplying N-digit x data by 3937 is N+4 digits. Therefore, during the calculation process, lower digits must be truncated (doing this will reduce calculation accuracy).
If this is not done, a result storage register of N+4 digits will be required. In the present invention, the multipliers are 2, 31 and 12.
7, the configuration of the multiplier circuit is simple, and the number of processing steps is reduced even when processing with a program. In the first embodiment, 2, 31, and 127 were used as the multipliers, but 31 is ( 32-1) and 127 is equal to (128-1
), so in the second embodiment shown in FIG.
(32-1) instead of 1, (12 instead of 127)
8-1) was adopted.

In FIG. 3, B is an arithmetic means for multiplying input data X2 by 32 and then subtracting X2, and C' is for multiplying input data X3 by 128 and then subtracting X. It is a calculation means.

It goes without saying that such a configuration can achieve the same functions as the first embodiment. Next, I dared to use (32-1) instead of 31, and (12-1) instead of 127.
Explain the effect of using 8-1).

Digital systems use binary codes.

Therefore, data values are often processed using binary codes instead of decimal codes. It is well known that, due to the nature of binary codes, when a binary code value is shifted one bit at a time to the upper side (left shift), a result equivalent to doubling the data is obtained.

Similarly, if the binary code value is shifted upward by 2 bits at a time, the data will be multiplied by 4, and if it is shifted upward by 3 bits at a time, the data will be multiplied by 8. Therefore, in order to multiply binary data by 32, there is no need to perform any complicated multiplication operation, and the data code is
Just shift it bit by bit.

Furthermore, in order to multiply binary data by 128, there is no need to perform any complicated multiplication operation, and it is only necessary to shift the data code to the upper side by 7 bits at a time. Thus, the arithmetic means A in FIG. 2 only needs to shift the input data X by 1 bit to the upper side, and the arithmetic means B' has the function of shifting the input data X2 by 5 bits to the upper side. The calculation means C' may be a means having only the function of subtracting X2 from the result, and the calculation means C' may have only the function of shifting the input data X3 to the upper side by 7 bits and the function of subtracting X3 from the result. As detailed above, in the inch-millimeter data conversion method of the present invention, the number of digits to be processed when converting data from inches to millimeters and from millimeters to inches is reduced. The above data conversion can be performed easily.

Therefore, it can be used in length measuring devices and the like.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing a data conversion method from inches to millimeters, FIG. 2 is an explanatory diagram of the first embodiment of the inch-millimeter data conversion method of the present invention, and FIG. FIG. 2 is an explanatory diagram of the second embodiment.

Claims (1)

[Claims] 1. A first calculation means for multiplying input data by 2;
It consists of a second calculation means for multiplying input data by 31 and a third calculation means for multiplying input data by 127. When converting input data in inches to data in millimeters, When converting input data in millimeters to data in inches by first doubling the input data in units by the first calculation means and then multiplying it by 127 by the third calculation means. In this method, input data in millimeters is first multiplied by 31 by a second calculation means, and then multiplied by 127 by a third calculation means. 2 As the first calculation means, a means having a function of shifting the input data to the higher order side by 1 bit is used, and as the second calculation means, means having the function of shifting the input data to the upper side of 5 bits, A third arithmetic means is used which has a function of subtracting the input data before shifting from the result data shifted to the side, and has a function of multiplying the input data by (32-1) as a result. has the function of shifting the input data to the upper 7 bits, and the function of subtracting the input data before shifting from the result data shifted to the upper 7 bits, and as a result, the input data becomes (128 -1) The inch-millimeter data conversion method according to claim 1, characterized in that means having a multiplication function is used.