Data storage apparatus and operation method thereof

Abstract

An operation method of a data storage apparatus includes performing a first read operation using an optimal read voltage on read-failed memory cells, performing ECC decoding operation on read data, performing a second read operation using an oversampling read voltage on the read-failed memory cells when the ECC decoding operation fails, determining whether potential error memory cells which are turned on through the optimal read voltage and are turned off through the oversampling read voltage are present in the read data, determining whether neighboring memory cells which share a bit line with the potential error memory cells and are coupled to neighboring word lines are in erased state when the potential error memory cells are present, and inverting bit values corresponding to the potential error memory cells in the read data from the read-failed memory cells through the first read operation when neighboring memory cells are in erased state.