| 摘要 |
PURPOSE:To improve reliability without deterioration in processing performance by making a majority decision when accessing a control word which disables retrying by microinstructions and entering a branch mode in other cases. CONSTITUTION:When an address for accessing a control memory (CS) 2 is set in an address register (CSAR) 1, control memories #1-#4 of CS2 are accessed simultaneously to output four control words. Processing for reading or arithmetic based upon read data can not be retried, so a branch mode signal is turned on and one of branch selection signals (e.g. a) is turned on in this case to fetch and set one of the control words of CS2 in a data register (CSDR) 4. When an arithmetic result is stored in a register, a majority decision mode signal is turned on since the retrying is impossible and a majority decision among the outputs of the memories #1-#3 of CS2 is made to set the result in CSDR. |
