Method for determining resistance calibration direction in ZQ calibration of memory device

Abstract

A method for determining a resistance calibration direction in ZQ calibration of a memory device includes: repeatedly comparing a reference voltage with an target voltage by a comparator to obtain an odd plurality of comparison outputs, each of the comparison outputs being one of a high-level state and a low-level state; determining a majority of the comparison outputs for their states by a ZQ calibration controller; and determining a resistance calibration direction according to the majority by the ZQ calibration controller so that the ZQ calibration controller generates a calibration code based on the resistance calibration direction and applies the calibration code to a resistance calibration unit to adjust the target voltage via the resistance calibration unit.

Dependencies are inferred from the claim text.