| 摘要 |
PURPOSE:To increase greatly the flexibility for application to various types of devices, by detecting the phase difference between the frequency division pulse and the sampling pulse sent from outside and then giving the control to the division ratio of the divider circuit within the fixed range. CONSTITUTION:Divider circuit 19 divides read/write clock 15 supplied from outside with the output of up-down counter 20, and then supplies division pulse 18 to A/D.D/A converter circuit 10. At the same time, the division output is sent to counter 21, and the output signal (g) is supplied to FF22 to detect the comparison difference of the rise phase of signal (g) against the rise edge of sampling pulse 14 of 8K Hz. Based on the comparison difference, the division ratio is controlled within the fixed range for circuit 19 via counter 20. Then pulse 18 is used for the internal working clock of circuit 10. Thus the flexibility can be increased greatly for the application to various types of devices. |
