| 摘要 |
PURPOSE:To reduce the burden of software by reporting displacement to a host computer to clear a counter only when a pointing device is moved. CONSTITUTION:Data inputted from the pointing device is divided to X and Y coordinates and is counted by counters 21 and 22. They are outputted to output registers 31 and 32 and output buffers 33 and 34 by a latch clock signal 106 outputted from a control circuit. OR between values 114 and 115 of output registers 31 and 32 is operated; and if this AND output 105 is not ''0'', the control circuit outputs an interruption signal. When a read signal 102 is inputted then, output buffers 33 and 34 output data signals 103 and 104, and the control circuit outputs a reset signal to counters 21 and 22 to clear them. Consequently, data reception request is reported to the host computer only when data is inputted from the pointing device.
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