| 摘要 |
PROBLEM TO BE SOLVED: To quickly finish overflow calculation and accordingly improve data processing efficiency. SOLUTION: This data processor has plural units 21 to 24 which are included in a register file and identified by each address. Each of units 21 to 24 has a register 31 which stores the data to show the calculation result, a register 32 which stores an overflow flag to show occurrence or non-occurrence of overflow in the calculation, and a register 33 which stores a sign flag to show whether the calculation result should be replaced with the positive or negative saturation if overflow occurred in calculation. Both overflow and sign flags are updated in response to the write signal that is related to the corresponding register 31. If the corresponding overflow flag is set when a read signal is given to a certain register 31, the positive or negative saturation is generated at the input side of an arithmetic unit in response to the sign flag. |
