This paper investigates the numerical issue of a discrete-time induction-motor emulator implementation. The stability analysis of the finite-word length implementation shows a coupling between required word length and the sample rate. We propose specific guidelines to analyze this coupling and to estimate the required data word length for both signals and coefficients of the model. To respect algorithm requirements, a FPGA-based implementation was used for architecture development. The direct torque control is implemented to verify in real-time the AC-motor emulator prototype.