| 摘要 |
PURPOSE:To constitute a title system so that a influence of an error which has been generated at the time of access to other system is not exerted on the own system to the utmost, by processing a command which is being monitored, as a buffer memory nullification command to the own system, even when an abnormality exists in said command. CONSTITUTION:All CPUs 10-13 always monitor a command on a system bus 42, and when a other system end command is detected, a nullification processing of BS of the own system is executed by utilizing its address. Even in case when an error of a command which is being monitored has been detected, the nullification processing is executed. As for a kind of the error, there are a parity error of a command code part of a received command, parity error of request destination - origin address parts, and an abnormality of a sending- out condition of TAG. When these errors have been detected, the buffer memory of the own sytem is brought to the nullification processing by using an address contained in the fourth - the seventh bytes of its command. |
