Delay estimation device and delay estimation method

A delay estimation device, comprising:

• a digitally controlled delay line (DCDL), receiving a first clock signal and generating a plurality of first phase signals based on the first clock signal;
• a time-to-digital converter (TDC), coupled with the DCDL and generating a first timing code based on the first phase signal and a second clock signal;
• a control circuit, coupled with the TDC, controlling the DCDL based on the first timing code;
• wherein the DCDL receives a third clock signal and generates a plurality of second phase signals based on the third clock signal;
• wherein the TDC generates a second timing code based on the second phase signal and a fourth clock signal;
• wherein the control circuit estimates a specific delay between the third clock signal and the fourth clock signal based on the second timing code;
• wherein the delay estimation device further comprises:
• a pulse generator for receiving a reference clock signal and outputting the first clock signal and the second clock signal in response to the reference clock signal, wherein the pulse generator comprises:
• a first D flip-flop (DFF), having a data input terminal, a clock input terminal, and an output terminal, wherein the clock input terminal of the first DFF receives the first clock signal, the data input terminal of the first DFF receives a predetermined data signal, wherein the first DFF outputs the first clock signal via the output terminal of the first DFF in response to a first rising edge in the first cycle of the first clock signal and the predetermined data signal, and the first DFF outputs the third clock signal via the output terminal of the first DFF in response to a third rising edge in the second cycle of the reference clock signal and the predetermined data signal;
• and
• a second DFF, having a data input terminal, a clock input terminal, and an output terminal, wherein the clock input terminal of the second DFF receives the reference clock signal, the data input terminal of the second DFF is coupled with the output terminal of the first DFF and receives the first clock signal, wherein the second DFF outputs the second clock signal via the output terminal of the second DFF in response to a second rising edge in the first cycle of the reference clock signal, and the second DFF outputs the fourth clock signal via the output terminal of the second DFF in response to a fourth rising edge in the second cycle of the reference clock signal;
• a mode selecting circuit coupled between the DCDL and the pulse generator, selectively outputting the reference clock signal or one of the first clock signal and the third clock signal to the DCDL in response to a first mode selection signal.

A delay estimation method, adapted for a delay estimation device comprising a pulse generator, a mode selecting circuit, a digitally controlled delay line (DCDL), a time-to-digital converter (TDC), and a control circuit, wherein the method comprises:

• selectively outputting, by the mode selecting circuit, a reference clock signal or a first clock signal to the DCDL in response to a first mode selection signal;
• receiving, by the pulse generator, the reference clock signal and outputting the first clock signal and a second clock signal in response to the reference clock signal;
• receiving the first clock signal from the pulse generator and generating a plurality of first phase signals based on the first clock signal by the DCDL;
• generating, by the TDC, a first timing code based on the first phase signal and a second clock signal;
• and
• estimating, by the control circuit, a specific delay between the first clock signal and the second clock signal based on the first timing code.