Number format conversion apparatus for signal processing

摘要

A number format conversion apparatus for signal processing has as inputs an exponent value and a mantissa value, the exponent and mantissa values representing a numerical value for a signal sample. An operator inputs an exponent max/min range and an offset, depending upon what conversion is desired. An output exponent is derived from the input exponent as a function of the maximum and minimum exponent values and the exponent offset. A shift value is derived from an unclipped output exponent and the minimum exponent value. The shift value is applied to a barrel shifter to shift the mantissa value to produce an output mantissa. The output exponent and mantissa form a floating point output number for the signal sample when a floating point output is selected, and the mantissa forms a fixed point output number for the signal sample when a fixed point output is selected. Thus a single circuit, implementable as a block on an ASIC, performs number format conversion between floating point and fixed point number formats.