The trigonometric function operation device null which uses pseudo division

摘要

PURPOSE:To obtain both sintheta and costheta at speed approximately equal to the conventional speed and with higher accuracy, by using a barrel shifter and two adders/subtractors. CONSTITUTION:The X and Y registers 111 and 121 store two types of variables. The adders/subtractors 112 and 122 perform the addition or subtraction and a barrel shifter 113 can shift the contents of the register 121 to the right by an optional even number of digits. Then a shifter 113 also doubles the output of the adder/subtractor 112 and outputs it to the register 111. While a shifter 124 multiplies the output of the adder/subtractor 112 by 1/2 and outputs it to the register 121. A constant ROM 104 stores the constants K and 1/K. An exponent part computing element 105 controls the shift number of the shifter 113 and the address of the ROM 104 to perform the arithmetic of the exponent part. Furthermore a stack 106 and a multiplier 107 are added. Thus it is possible to calculate both sintheta and costheta at high speed and with high accuracy by means of a barrel shifter and two adders/subtractors.