| 摘要 |
PURPOSE:To reduce the load of software by providing a rounding control part to control the rule which rounds the arithmetic result of a computing element into the limited number of bits. CONSTITUTION:A computing element 4 calculates the values inputted to its inputs 8 and 9 and performs a rounding operation based on the rule set at a rounding control part 7. The part 7 sets the latest rounding rule with a range arithmetic instruction, for example, and then decides a rounding rule to obtain the second approximate value to the true value based on the latest rounding direction and the type of the range arithmetic instruction after the element 4 finished the calculation to obtain the value most approximate to the true value. This decided rounding rule is set to the element 4. Thus an error range is easily obtained with the true value shown in the ranges of the most and second approximate values. Furthermore the software load can be reduced since the rounding rules are changed within a mechanism. |
