Silicon Works Co., Ltd.

Chul Soo Jeong

Yong Hwan Moon

Sang Ho Kim

Jae Ryun Shim

Jun Ho Kim

Young Soo Ryu

The present invention relates to a false lock prevention circuit and method which is used to cause a delayed locked loop (DLL) to escape from false lock such as harmonic lock or stuck lock, when the false lock occurred in the DLL, and a DLL using the same. The false lock prevention circuit includes a harmonic lock detector configured to detect harmonic lock and a stuck lock detector configured to detect stuck lock. The harmonic lock detector includes a plurality of flip-flops configured to sample a plurality of delayed clocks and a logic unit. The harmonic lock detector compares a reference clock signal with the plurality of delayed clock signals, and detects whether or not the positive edges deviate from one cycle of the reference clock signal.

Circuit and method for preventing false lock and delay locked loop using the same

Provided is a pre-emphasis circuit which transmits a pre-emphasis output current to an output node of an output driver in response to first to fourth pre-emphasis control signals generated by a logical operation on differential input signals. The pre-emphasis circuit includes: a first pre-emphasis circuit driven in a range between a first voltage and a second voltage and configured to generate a first pre-emphasis output current in response to the first and second pre-emphasis control signals and output the generated first pre-emphasis output current to a first output node of the output driver; and a second pre-emphasis circuit driven in the range between the first voltage and the second voltage and configured to generate a second pre-emphasis output current in response to the third and fourth pre-emphasis control signals and output the generated second pre-emphasis output current to a second output node of the output driver.

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Daejeon-si, South Korea

Chul Soo Jeong