Patent ID: 7945607

Claim:
A data processing apparatus comprising: a data processing unit operable to execute instructions; the data processing unit being responsive to a format conversion instruction to apply a format conversion operation to a number to perform a conversion between a fixed-point representation of said number and a floating-point representation of said number, a control field being arranged to provide a programmable value specifying a decimal point location within the fixed-point representation of said number, and the data processing unit being operable to reference the control field and to control the format conversion operation in accordance with the programmable value; wherein the format conversion instruction is a fixed-point to floating-point conversion instruction and the format conversion operation applied to the number is operable to perform a conversion from a fixed-point representation of said number to a floating-point representation of said number, wherein the format conversion operation includes an exponent generation operation operable to generate an exponent value for the floating-point representation of the number by performing an operation equivalent to subtracting from an initial exponent value a value indicative of the number of leading zeros in the fixed-point representation of the number, and the format conversion operation being operable, prior to said exponent generation operation, to adjust the initial exponent value based on the programmable value provided within the control field.