Patent ID: 7576560

Claim:
An apparatus for measuring an on-die termination (ODT) resistance, comprising: an ODT controller configured to receive a plurality of decoding signals, a first test mode signal, and a second test mode signal, and generate a plurality of pull-up signals and a plurality of pull-down signals, the pull-up signals being enabled in response to the decoding signals and the first test mode signal, the pull-down signals being enabled in response to the decoding signals and the second test mode signal; and a driver configured to receive the pull-up signals and the pull-down signals, and drive a data terminal, wherein the ODT controller comprises: a first pull-up/pull-down signal generator configured to generate a first pull-up signal and a first pull-down signal, such that the first pull-up signal and the first pull-down signal are enabled in response to a first decoding signal when the first test mode signal and the second test mode signal are in a disabled state, the first pull-up signal is disabled when the first test mode signal is in an enabled state, and the first pull-down signal is disabled when the second test mode signal is in an enabled state; and a second pull-up/pull-down signal generator configured to generate a second pull-up signal and a second pull-down signal, such that the second pull-up signal and the second pull-down signal are enabled in response to a second decoding signal when the first test mode signal and the second test mode signal are in the disabled state, the second pull-up signal is disabled when the first test mode signal is in the enabled state, and the second pull-down signal is disabled when the second test mode signal is in the enabled state.