| 摘要 |
PURPOSE:To reduce the system stop by reading out data again from the other directory position and using it for retrieving a directory, when a parity error is detected in the data from one directory position. CONSTITUTION:In the case a value of an error retain register 15 is logic '1', a retrieval of a directory 2a is executed again. In this case, since a value of a directory address switching register 11 is inverted, an output of an exclusive OR circuit 12 is logic '1'. When a parity error is detected again in data read out of the directory 2a, an output of a parity checker 8 becomes logic '1', and since the value of the register 15 is logic '1', an output of an AND circuit 14 becomes logic '1' and logic '1' is set to an error register 9. Also, when an error report is executed, the system stops. However, unless the parity error is detected in the data read out again, the processing of a cache access is executed by setting logic '1' to one of a hit register 5 or a miss register 7. |
