Most of safety-critical embedded software, such as y-by-wire control programs, performs a lot of oating-point computations. High level specications are expressed in a formal model edited manually in SCADE through a graphical interface. It generally handles numerical variables and constants as if they were ideal real numbers. This work, for the purpose of numerical accuracy analysis, presents a new version of an Automatic Code Generator (ACG). This tool transforms high-level models into C codes and performs static computations by using multiple-precision arithmetic. This article describes a successful way of controlling computation accuracy of numerical constants in an Automatic Code Generator. An accuracy analysis on numerical constant values is presented in a case study.