| 摘要 |
PURPOSE:To obtain a skew compensation system of an interface that can obtain the maximum data transfer speed corresponding to the length of a cable by providing necessary skew compensation time according to actual length of the cable. CONSTITUTION:A counter 2-4 starts counting of clock (d) by an instruction (a) of a microprocessor 2-1. Then, an out-tag (e) is sent from a channel device and the counter 2-4 stols. Count value at the time of stopping is obtained from a value corresponding to a reply signal by selecting the number of repetition of the clock signal (d) to a sufficient value for the time from transmission to reception of in-tag. This count value (f) is decoded and added to a selector circuit 2-7. Delay output (g) is selected in response to output of another delay circuit 2-6, and inputted to an output data register 2-8 as clock input, and bus out is taken in. Thus, sampling of bus-out can be set automatically according to the length of the cable. |
