Developments trends in commercial drives point that that the next generation of them includes some sort of sensorless torque control. Using the 'spare' processing power of a digital signal processor (DSP) to implement these techniques can significantly reduce the overall system cost of an electrical drive, but requires relatively complex mathematical algorithms to estimate the mechanical quantities by software. Usual tool for development of such algorithms are specialized modeling language such as MATLAB. Since they are originally made in full precision floating point software, its finite precision hardware realization can introduce additional problems. This paper investigates related problems, proposing a fair and simple algorithm that can be used for flux estimation. Both simulation and experimental results are presented