Patent ID: 6167421
Filing Date: 2000-12-26
Classification: G06F

Abstract:
A method of performing an iteration in an iterative method of multiplying a multiplicand by two or more 2-bit portions of a multiplier in a data processing apparatus, wherein each of the 2-bit portions of the multiplier is binary encoded to represent any of the numbers 0, 1, 2 and 3, the method comprising the steps of:selecting one of the 2-bit portions of the multiplier in the data processing apparatus;performing a first pass operation that comprises the steps of:generating a first partial product representing the multiplicand multiplied by a value that is equal to the selected 2-bit portion of the multiplier if the selected 2-bit portion of the multiplier is not equal to 3, and representing the multiplicand multiplied by a value that is equal to minus one if the selected 2-bit portion of the multiplier is equal to 3; andconditionally setting a flag if the selected 2-bit portion of the multiplier is equal to 3; andperforming a second pass operation that comprises the step of conditionally adding a value of 1 to a next 2-bit portion of the multiplier if the flag is set.