Method and apparatus for converting an analog signal to a digital floating-point number and a digital floating-pont number to an analog signal.

摘要

A method for converting an analog signal to a digital floating-point number and a digital floating-point number to an analog signal. According to the invention, A/D conversion is performed by forming a logarithmed signal (log¦x¦ ) from an analog signal (x) by a logarithmic function having an arbitrary base, converting the resultant signal to digital form (z) by fixed-point A/D conversion, separating the exponent (c) of the floating-point number from the digitized sample value and calculating the mantissa (mq) of the floating-point number from the fractional part (f) by a base 2 exponential function. Correspondingly, D/A conversion is performed by converting the mantissa (mq) of the floating-point number by a logarithmic function having an arbitrary base to the exponent of the base, adding the converted mantissa and exponent, converting the digital number (z2) obtained by conversion to an analog signal by fixed-point D/A conversion, and forming from the converted signal a signal that represents its base 2 exponent. <IMAGE> <IMAGE>