| 摘要 |
PROBLEM TO BE SOLVED: To selectively reset only a SCSI device which has hung up by receiving a reset(RST) signal and resetting this device when this device is outputting a busy(BSY) signal. SOLUTION: If the SCSI device 2 hangs up, a driver circuit 52 makes the BSY signal 5 on a SCSI bus 3 active. A reset condition decision circuit 7 receives the RST signal 6 on the bus 3 and resets its device only when a SCSI controller 4 drives the BSY signal 5 (an enable signal 53 is active) or when the BSY signal 5 on the bus 3 is inactive (the output of a NOT circuit 71 is active). An AND circuit 73 masks the RST signal 6, which is not transmitted to the RST terminal of the SCSI controller 4, so that other devices 2 will not be reset.
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