Title:
ELECTRONIC DESK CALCULATOR
Document Type and Number:
Japanese Patent JPS5783863
Kind Code:
A
Abstract:
PURPOSE:To obtain an output range of an answer which is equivalent to the range of the input data for an operation of (x<2>+y<2>)<1/2>, by performing a calculation based on the value with which the absolute value of x/y or y/z becomes <=1 and avoiding the occurrence of an overflow in a square calculation. CONSTITUTION:When a program storage device U1 gives an instruction code to a program storage device U2, the device U2 compares 8 the absolute value of an (x) register U6 with that of a (y) register U7. If ¦x¦<¦y¦ is satisfied, the device U2 controls a dividing device U10 by a division instruction code given to the U2 from the device U1 and then stores the value of x/y in a register U6. After this, a square arithmetic device U3 squares the calculated value of the register U6 by a square instruction code. Then a +1 addition U5 is carried out by a +1 addition instruction code, and this output receives an operation of the extraction of square root U4 by a square root extraction instruction code. The output of the U4 is multiplied U6 by the value ¦y¦ by a multiplication instruction code. When the absolute value of (x) is larger than that of (y) through a comparison by a comparator 8, these absolute values are exchanged with each other to perform an operation.
Inventors:
NAKAMURA TERUAKI
Application Number:
JP15900480A
Publication Date:
May 25, 1982
Filing Date:
November 12, 1980
Export Citation:
Assignee:
NIPPON ELECTRIC CO
International Classes:
G06F7/38; G06F7/00; G06F7/76; G06F15/02; (IPC1-7): G06F7/00