摘要 |
A delay locked loop (DLL) device includes a first and a second input buffers for receiving an external clock, a multiplexer for selectively outputting a first and a second internal clocks based on a most significant bit (MSB) signal, a delay means for delaying the first and the second internal clock which is selected by the multiplexer, a phase detector for comparing a phase of the first internal clock with that of a feedback clock which is feedbacked from the delay means to thereby output a comparing signal, a low pass filter (LPF) mode generator for outputting a locking signal, which checks a locking state of the feedback clock based on the comparing signal and a first and a second control signals, to the delay means, and a low pass filter for receiving the comparing signal to inform whether or not the comparing signal is erroneous to the delay means.
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