Patent ID: 8619492

Claim:
An on-die termination (ODT) circuit, comprising: a first termination circuit including a first switch and configured to switchably connect a first termination impedance between an input/output data node and a first power supply voltage; a second termination circuit including a second switch and configured to switchably connect a second termination impedance between the input/output data node and the first power supply voltage; and a switch-control circuit configured to perform a logic operation on an output enable signal (DOEN) and an asynchronous control signal (ACS) to output a first switch-control signal and a second switch-control signal to selectively activate the first termination circuit and the second termination circuit, respectively, to selectively connect the first termination impedance, the second termination impedance, or both the first termination impedance and the second termination impedance between the input/output data node and the first power supply voltage; wherein the first switch-control signal is not configured to control a switch to switchably connect a termination impedance between the input/output data node and a second power supply voltage during a memory READ mode nor during a memory WRITE mode; wherein the second switch-control signal is not configured to control a switch to switchably connect a termination impedance between the input/output data node and the second power supply voltage during the memory READ mode nor during the memory WRITE mode.