| 摘要 |
PURPOSE:To improve activity efficiency in a main bus, by receiving once a command from a central processor to a peripheral controller connected to an expansion bus by a repeater, making only the coincidence of group numbers a condition. CONSTITUTION:A group channel register 53 holds the group channel numbers of peripheral controller group connected to an expansion bus 3. The most significant 4 bits of a command channel number from the central processor on a main bus 1, and the content of the group channel register 53 are checked by an address comparison circuit 52, and when they are coincided, the fact is informed to a transfer control circuit 56, then a main bus interface control circuit 51 is controlled. A bit of command information fetched through the main bus interface control circuit 51 is stored at a buffer 54 once, and is outputted onto the expansion bus 3 through an expansion bus interface control circuit 55. |
