| 摘要 |
PURPOSE:To control an I/O interface at a high speed with the less number of times of response than a conventional system by transferring a frame where an encoded I/O interface signal is carried between a channel device and an I/O device through a loop transmission line. CONSTITUTION:The channel device 2 transmits the frame to which the code (10)16 of a SEL1 is set in an interface control field in order to activate a disk device 6. This frame is first received by a disk controller 3 through a route 8a, however, it is transmitted to a route 8b as it is, because a transmission destination address set to the frame is different from the address of its own device. Receiving the frame, a disk controller 4 checks the state of the disk device 6 specified by the device address of the frame and returns a response frame to the channel device 2 through the route 8c of a loop transmission line 8. Information exchanged by the activation sequence is equivalent to a conventional technique, but the necessary number of response times of the interface goes to one-fifth. Moreover the signal transfer time on the interface can be reduced to one-fifth, thereby speeding up interface processing. |
