| 摘要 |
PURPOSE:To prevent bit errors in data about measured distances so as to enable distance measurement at high speed and high accuracy by correcting the results of computations through rightward logical shifts only if overflow occurs. CONSTITUTION:A value counted by an overflow counter (OC)6 is set at zero and a distance measuring sensor I1 is 1 latched. 16-bit data I1 read are converted into N-bit data by a bit shifter 2 and 5 stored. Next, data I2 are 1 latched and 2 converted into N-bit data, which are then 5 transferred to a bit shifter 6. Then the data I1, I2 are 3 added together and the result of detection of overflow is 4 stored. When the content of the reference 4 is zero, the results of computations are 5 output, while when the content is 1 the data, I1, I2 of the shifters 2, 6 are subjected to rightward logical shifts and arithmetic 3 is performed. Also when the content is 1 the data are similarly shifted and subjected to increment 6 and then arithmetic 3 is performed; this process is repeated until the content becomes zero. When the content becomes zero, the number of times of overflow counted by the OC6 is read and the logical shifts to which the results of computations have been subjected are subjected to correction operations and are then 5 stored, and then the next arithmetic is started. |
