Data processing unit for converting a number between fixed-point and floating-point formats responsive to a conversion instruction.

摘要

Disclosed is a data processing unit that, when instructed to, converts a number from fixed point format to floating point format. The unit has a control field used to hold a programmable value that specifies the location of the decimal point. The unit references the control field when converting the format of a number. The control field may be in the form of a control register or within the format conversion instruction as an immediate value within the control field. The control field may identify an operand register in the programmable value is stored. The processing unit may be a pipeline processor. The exponent generation operation may be equivalent to subtracting from an initial exponent value the number of leading zeros in the fixed point number. The unit may also convert from floating point to fixed point. The floating point number may be provided as a exponent and a significand value and the conversion including a determination of a shift value and a shift operation applied to the significand value.