Patent ID: 7176711
Filing Date: 2007-02-13
Classification: H04L

Abstract:
1. An on-die termination (hereinafter, referred to as ‘ODT’) impedance calibration device comprising: a pulse generator for receiving a first enable signal supplied during an initial operation state and a second enable signal supplied from an exterior during a normal operation state and outputting a multi-pulse for calibrating an ODT impedance corresponding to reception of each of the first enable signal and the second enable signal; an M-bit counter and an N-bit counter for counting the number of pulses of the multi-pulse; a first maximum counter trigger signal generator for being enabled by the second enable signal and outputting a signal for disabling the pulse generator upon receiving a signal from the M-bit counter, the signal corresponding to a result of M bit counting of pulses of the multi-pulse; a second maximum counter trigger signal generator for being enabled by the first enable signal and outputting a signal for disabling the pulse generator upon receiving a signal from the N-bit counter, the signal corresponding to a result of N bit counting of pulses of the multi-pulse; a delay unit for delaying the multi-pulse for a predetermined period of time; an update trigger signal generator for controlling a time point for output control of the multi-pulse by outputting a pulse signal, which is toggled by a delay multi-pulse output from the delay unit, as an update signal to the pulse generator in an enable state of the first enable signal; and an ODT impedance calibration unit for receiving the multi-pulse and outputting a control signal for calibrating an ODT impedance.