| 摘要 |
In a frequency control arrangement 200 of the type comprising an oscillator 270, a mark or space counter 210, a frequency detector 220 and an error signal calculator 230 - 260, 290 and in which it is desired to control the oscillator 270 to resonate at a frequency substantially equal to the frequency of a received data stream, the oscillator 270 is implemented as a four phase ring oscillator (Figure 1, ref 110) arranged to provide phased clock signals to the mark or space counter (Figure 1, ref 100). This allows the mark or space counter to be arranged to measure the length of the marks or spaces of the data with increased resolution. <IMAGE> |
