Patent ID: 7412476
Filing Date: 2008-08-12
Classification: G06F

Abstract:
1. A system for decimal multiplication in a superscaler processor comprising: a first pipeline including: a first register; a second register; a third register; an execution unit including a bit logic unit and a binary adder in operable communication with said first register, said second register, and said third register; a first rotator in operable communication with said first register and said execution unit; and a carry register in operable communication with said execution unit; a second pipeline comprising: a fourth register; a fifth register; a sixth register; a second execution unit including another bit logic unit and another binary adder in operable communication with said fourth register, said fifth register, and said sixth register; and a rotator in operable communication with said fourth register and said execution unit; a third pipeline comprising: a seventh register; a eighth register; a ninth register; a decimal adder in operable communication with said seventh register and said eighth register, a rotator in operable communication with said ninth register; a general register file for storage and retrieval of data; an operand buffer for obtaining a first operand and a second operand; and a communication bus for communication among at least two of said first pipeline, said second pipeline, said third pipeline, said general register and said operand buffer; wherein a multiplier, a multiplicand, an effective multiplier and an effective multiplicand are established from a significant digit comparison between said first operand and said second operand; and a partial product term is generated and accumulated every two cycles; wherein said partial product terms are created from said effective multiplicand and multiples of said effective multiplier, said multiples stored in the general register file, said multiples being ones times said effective multiplier, two times said effective multiplier, four times said effective multiplier and eight times said effective multiplier and said partial product terms are added to an accumulation of previous partial product terms shifted one digit right such that a digit shifted off is preserved as a result digit.