Data processing system for single-precision and double-precision data

A data processing system comprising:

• first, second, third, and fourth receiving means for receiving a first data, a second data, a third data, and a fourth data, respectively, each of said first to fourth data forming a single-precision data in a single-precision operation mode, said first and second data forming a first double-precision data in a double-precision operation mode, said third and fourth data forming a second double-precision data in a double-precision operation mode;
• a single-precision data to double-precision data conversion unit, connected to said second and fourth receiving means, for converting said second data of a single-precision data type and said fourth data of a single-precision type into third double-precision data and fourth double-precision data, respectively, in a single-precision operation mode;
• a single-precision operation unit, connected to said first and third receiving means, for performing a single-precision operation upon said first and third data to obtain a first single-precision result data in a single-precision operation mode;
• a double-precision operation unit, connected to said first to fourth receiving means, and to said single-precision data to double-precision data conversion unit, for performing a double-precision operation upon said third and fourth double-precision data in a single-precision operation mode and for performing a double-precision operation upon said first and second double-precision data in a double-precision operation mode, to obtain a double-precision result data;
• a double-precision data to single-precision data conversion unit, connected to said double-precision operation unit, for converting said double-precision result data to a second single precision result data in a single-precision operation mode;
• and
• transmitting means, connected to said single-precision operation unit, said double-precision data to single-precision data conversion unit, and said double-precision operation unit, for transmitting said first and second single-precision result data to an exterior in a single-precision mode, and for transmitting said double-precision result data to the exterior in a double-precision operation mode wherein in said double-precision operation mode, only said double-precision operation unit operates and said single-precision operation unit is non-operational and in said single-precision operation mode, said double-precision and single-precision operation units operate simultaneously.