JPS5582576A - Data pick up method - Google Patents

Abstract

PURPOSE:To automatically assure the optimum slice level at all times even with the variation of data level, by counting the clock signal of a given period to convert into analog value and to form desired slice level, and by picking up the information by it. CONSTITUTION:The clock of the oscillator 13 is counted at the counter 14, it is converted into analog value at the D/A converter 15 to consitute it as the slice level of the first comparator 21. Accompanied with the increase in the count value of the counter 14, the slice level is increased and it reaches the lower limit V2, then Fleming code detection pulse is produced from the Fleming code detection circuit 25 and the count corresponding to the level V2 is latched to the first register 16. When the count value increases and it reaches the upper limit V1 for the slice level, the detection pulse of the circuit 25 is stopped, the gate 28 outputs the slice level dltection signal of upper limit and latches the second register 17. The output of the registers 16, 17 is added 18 and divided 19 into 1/2 value to obtain the intermediate value V0 for the output of the D/A converter 20, and the comparator 22 slices DATA at this V0.