| 摘要 |
PURPOSE:To execute efficiently a data transfer between optional devices without informing and decoding a device number by each device, when transferring a data between each device, by providing plural separate device signal lines and a common signal line. CONSTITUTION:Separate device signal lines 12 send separately a bus use request to a bus control device 30 from a processing device 20, and separate device signal lines 13 send separately a bus use permission from the device 30 to the device 20 which has generated the bus use request. Also, a common signal line 14 sends a signal for informing in advance a receiving time of a data to the device 20 of a receiving side, when transferring a data between the device 20(i) and 20(j), or to the device 20 from the device 30. Transmission and reception of a data between the device 20 and 30, and between the device 20(i) and 20(j) are executed optionally and selectively through a bus 10 constituted of these signal lines, by which each device is controlled so as to communicate to only a main storage 40 through the device 30 at all times. That is to say, each device can transfer a data efficiently without executing information, etc. of a device number. |
