| 摘要 |
PURPOSE:To position a magnetic head at a target track with high precision by forming with operation the double phase servo control information based on the difference information showing a shift amount as well as the reverse information showing a positioning direction given from an upper device. CONSTITUTION:The upper device supplies reverse =0 of the reverse information showing the positioning direction corresponding to the present track type (b) of a magnetic head 8, difference 2=0, 1=1, and the like of the difference information showing a shift amount, and the like. These information are delivered to a full adder circuit 3 via exclusive OR circuits 1 and 2, and augends D2, D1, and the like are calculated. Then the differences 2=1, 1=0, reverse =0, are supplied as the target position information of a type (d) of the head 8. Thus the outputs E2 and E1 of the circuits 1 and 2 are defined as addends for calculation with those augends D2 and D1. Then the double phase servo control data is stored to a register circuit 4. In such configuration, the head position control information is produced accurately and a target track is accessed with high precision. |
