| 摘要 |
PURPOSE:To evade the repetitive output of the same significant output data by rewriting all bits of mask data into a masked state. CONSTITUTION:A process data input/output (PIO) controller 20 is provided with gates (G) 201-203. The gate G201 is a receiver gate connected to an input/ output bus 14 and the G203 is a driver gate connected to the data bus of a PIO bus 16. Data received by the G202 is held in a data register DR204 and an address received by the G202 is held in an address register AR205. Inherent data for specifying all data as insignificant data is held previously in a mask data register MR206. |
