Saturation select apparatus and method therefor

摘要

A saturation select apparatus and method are implemented. Late stage logic blocks in an adder are provided which combine saturation select control signals with sum generating signals. A first saturation select control is asserted in response to an unsigned saturated instruction, and a second saturation select control is asserted in response to a signed saturated instruction. If either select control is asserted, each logic block outputs a corresponding bit of a respective saturation value. In response to a modulo mode instruction, both select control signals are negated, and each logic block outputs a corresponding bit of the arithmetic operation (sum or difference) implemented by the instruction.