| 摘要 |
PURPOSE:To realize the on-line maintenance of an arbiter by using an arbiter connected to an arbitration bus, a service interuption detecting circuit which detects the service interruption of the power supplied to its own system, and an arbiter right control circuit. CONSTITUTION:When a CTL card of the control side is pulled out, the service interruption detecting signal INZC is set at an L level and an FF 2 is reset. Then the CTL side abandons the arbitration ARB right. When the FF 2 is reset, the ARB right ARBC of the control side and the normal signal RDYC of the control side are set at H levels. An FF 1 of the waiting side is set when the ARB change permission signal ACHGS is kept at an L level to acquire the ARB right and the signal ARBS is set at an L level. When the CTL card is inserted, the signal INZC is set at an H level and the FF 1 can be set. At the same time, FF 1 is reset when the signal RDYC is set an L level and adandons the ARB right with the signal ARBS set at an H level. The FF 2 is set when the signal ACHGC is kept at an L level and acquires the ARB right.
|
