Method and apparatus for executing division
OwnerJaako Vihrialainventor
Life of this patent
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Abstract
A method of executing division and an electronic apparatus implementing the method are provided. In the method, an auxiliary divisor is retrieved from a look-up table stored in the electronic apparatus, the auxiliary divisor being a predetermined number generated by the product of the powers of the integer two and the reciprocal of the divisor. In the method, the division is executed in the electronic apparatus by multiplying the dividend of the division by the auxiliary divisor. The result of the division is scaled in the electronic apparatus in order to represent it in the desired form by shifting the result obtained by multiplying.
Claims24
A method of executing division in an electronic apparatus, characterized by
- (112) retrieving an auxiliary divisor from a look-up table stored in the electronic apparatus, the values of the auxiliary divisor in the look-up table being predetermined numbers generated by the product of the powers of the integer two and the reciprocal of the divisor and stored in the look-up table;
- (114) division is executed in the electronic apparatus by multiplying the dividend of the division by the auxiliary divisor retrieved from the look-up table;
- (116) scaling the result of the division in the electronic apparatus in order to represent it in the desired form by shifting the result obtained by multiplying.
A method as claimed in any one of the preceding claims, characterized by Q(y) being the integer 16 when the absolute value of divisor y is less than 32.
A method as claimed in any one of the preceding claims, characterized by Q(y) being the integer 21 when the absolute value of divisor y is greater than or equal to 33.
A method as claimed in any one of the preceding claims, characterized by the scaled result of the division being presented in the Q8 format.
A method as claimed in any one of the preceding claims, characterized by optimizing the Q format, in which the scaled result of the division is presented.
A method as claimed in any one of the preceding claims, characterized by checking, before the execution of the division, that the divisor and the dividend fulfil the initial conditions of the method.
An electronic apparatus for executing division, characterized in that the apparatus comprises:
- a look-up table (304), in which auxiliary divisors are stored, the values of the auxiliary divisors being predetermined numbers generated by the product of the powers of the integer two and the reciprocal of the divisor and stored in the look-up table;
- means (302) for retrieving an auxiliary divisor from the look-up table (304);
- means (302) for executing the division by multiplying the dividend of the division by the auxiliary divisor retrieved from the look-up table;
- means (302) for scaling the result of the division by shifting the number obtained as the result of the division obtained by multiplying in order to represent it in the desired form.
Dependencies are inferred from the claim text.