JPH0610435Y2 - Small electronic calculator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a small electronic computer having an ^xy calculation function.

[Prior Art and its Problems] Conventionally, all calculations of x ^{y in} a small electronic computer, for example, a calculator are performed according to a routine of x ^y . This means that x = 10 and y = n (n is an integer)
Even in the case of such a simple calculation, the ^xy routine is used, and therefore, the calculation speed could not be improved even in such a calculation.

[The purpose of invention] This invention has been made in view of the above circumstances, the computation of x ^y, (n is an integer) x = 10, y = n compact electrostatic capable of improving the operational speed during The purpose is to provide a formula calculator.

[Points of Invention] In this invention, x is 10 or -1 in the calculation of ^xy.
If 0 is determined, it is determined whether y is an integer and whether y is an even number or an odd number. If x is 10 and y is an integer,
Is -10 and y is an even number, the mantissa part of the solution is "1", the exponent part is the value of y, and when x is -10 and y is an odd number, the mantissa part of the solution is "-1", the exponent part Is set as the value of y.

[Embodiment of the Invention] An embodiment of the invention will be described below with reference to the drawings.

FIG. 1 shows the circuit configuration of the embodiment. In the figure, reference numeral 1 denotes a key input unit, which includes a numeric key 1a, a function key 1b, an " ^xy " key 1c,
It has an "EXE" key 1d. The key input data of the key input unit 1 is sent to the control unit 2.

The control unit 2 is composed of a ROM and stores a program for controlling each circuit in advance. In this case, the control unit 2 is adapted to give a control command to the arithmetic register 3, R / W control unit 4, operation unit 5, X determination section 6, Y determination section 7,10 ^y calculation unit 8.

The calculation data of ^xy input from the key input unit 1 is R /
It is given to the expression buffer 9 via the W control unit 4. Also,
The contents of the expression buffer 9 are sent to the calculation unit 5 via the R / W control unit 4 and given to the calculation register 3. The operation register 3 has an X register 31 in which x is written, a Y register 32 in which ^y is written, and a Z register 33 in which the operation result of x ^y is written. The contents of the X register 31 of the operation register 3 are given to the X judging unit 6, and the contents of the Y register 32 are given to the Y judging unit 7. Here, the X determination unit 6
Detecting whether x is 10 or -10, the Y determination unit 7 determines whether y is an integer and whether it is an even number or an odd number. Then, the X determination unit 6 detects x = 10, and Y
When y is determined to be an integer by the determination unit 7, x = x is determined by the X determination unit 6.
When −10 is detected and the Y determination unit 7 determines that y is an even number, the 10 ^y calculation unit 8 sets the mantissa part of the Z register 33 of the calculation register 3 to “1”, the exponent part to the value of y, and X When the determination unit 6 detects x = -10 and the Y determination unit 7 determines that y is an odd number, the 10 ^y operation unit 8 causes the mantissa part of the Z register 33 of the operation register 3 to be “−1” and the exponent part to be The value of y is set. Of course, when the above-mentioned conditions are not judged by the X judgment unit 6 and the Y judgment unit 7, the usual calculation of ^xy is executed, and the solution is the Z register 3 of the calculation register 3.
Will be written in 3.

The display unit 10 displays the contents of the expression buffer 9 and the operation register 3.

Next, the operation of the embodiment thus configured will be described.

Now, when the formula data of “A”, “x ^y ”, and “B” is input from the key input unit 1 by using the numeric keys 1a and the “x ^y ” key 1c, the input data is transmitted via the R / W control unit 4. Is written in the expression buffer 9 and displayed on the display unit 10. When the "EXE" key 1d is operated in this state, the contents of the expression buffer 9 are read out to the calculation section 5 via the R / W control section 4, and the flow chart shown in FIG. 2 is executed. Here, if it is the calculation of ^xy , YES is determined in step A1, and the process proceeds to step A2. If NO is determined in step A1, another calculation is executed.

In step A2, the input value "A" of x is calculated in the arithmetic register 3
The input value “B” of y is written in the X register 31 of the Y register 32 of the arithmetic register 3. And step A
In step 3, the X determination unit 6 determines whether x in the X register 31 is 10, and in step A4, the Y determination unit 7 determines whether y in the Y register 32 is an integer. Here, step A3,
If NO is determined in at least one of the steps A4, the process proceeds to step A5, the usual operation of ^xy is performed, the result is written in the Z register 33 of the operation register 3, and the process ends. When YES is determined in both step A3 and step A4, the process proceeds to step A6 and Y
It is determined whether y of the register 32 is within the calculation range. here,
If NO, error processing is performed. On the other hand, if YES, the process proceeds to step A7, where the 10 ^y calculation unit 8 calculates the calculation register 3
"1" is written in the mantissa part of the Z register 33 of.

Next, in step A8, the X determination unit 6 determines whether x in the X register 31 has a losing sign. Here, when X is positive and NO is determined, the process proceeds to step A10 and 10 ^y
The operation unit 8 writes “y” in the exponent part of the Z register 33 of the operation register 3, and the processing is ended. On the other hand, if x is negative and YES is determined in step A8, step A
In step 9, the Y determination unit 7 determines whether y in the Y register 32 is an even number. Here, if y is an even number and YES is determined in step A9, the process proceeds to step A10, in which the 10 ^y operation unit 8 writes “y” in the exponent part of the Z register 33 of the operation register 3, and the process ends. Also, step A
In 9 it is determined that y in the Y register 32 is an odd number, and if NO, the process proceeds to step A11. In step A11, 10
^{The y} operation unit 8 writes "-1" to the mantissa part of the Z register 33 of the operation register 3, and then writes "y" to the exponent part of the Z register 33 of the operation register 3 to finish the process.

Therefore, in this way, in the calculation of x ^y , x = 1
0, y = n (n is an integer), instead of the conventional x ^y routine, x is 10 and y is an integer, and x is −1.
If 0 and y is an even number, the mantissa part of the solution is "1", and the exponent part is y.
Since x is -10 and y is an odd number, special processing is performed such that the mantissa part of the solution is "-1" and the exponent part is the value of y. The number of steps for accurate calculation can be minimized, and the calculation speed can be improved.

[Advantage of the Invention] According to the present invention, when x is determined to be 10 or −10 in the calculation of ^xy , it is determined whether y is an integer and whether y is an even number or an odd number. Is an integer, or x is -10 and y is an even number, the mantissa part of the solution is "1", the exponent part is the value of y, and when x is -10 and y is an odd number, the mantissa part of the solution is "-1", since the exponent was set as the value of y, the calculation of ^{x y, x = 10, y} = n (n is an integer) can improve the calculation speed during.

[Brief description of drawings]

FIG. 1 is a block diagram showing the circuit configuration of an embodiment of the present invention, and FIG. 2 is a flow chart for explaining the operation of the embodiment. 1 ... Key input part, 1a ... Numerical key, 1b ... Function key, 1c ... " ^xy " key, 1d ... "EXE" key,
2 ... Control unit, 3 ... Operation register, 31 ... X register, 3
2 ... Y register, 33 ... Z register, 5 ... Arithmetic unit, 6 ...
X determination unit, 7 ... Y determination unit, 8 ... 10 ^y calculation unit, 9 ... Expression buffer, 10 ... Display unit.

Claims (1)

[Scope of utility model registration request] 1. A small electronic computer having an arithmetic function of x ^y , a detecting means for detecting whether x is 10 or −10, a determining means for determining whether y is an integer, and y.
Discriminating means for discriminating even and odd numbers of x, and when x is 10 and y is an integer, and when x is -10 and y is an even number, the mantissa part of the solution is "1", the exponent part is the value of y, and x is A small electronic calculator comprising: a calculation unit for setting a mantissa part of a solution to "-1" and an exponent part to a value of y when -10 is an odd number.