SEMICONDUCTOR MEMORY DEVICE AND METHOD ANALYZING READ FAIL THEREOF

摘要

A semiconductor memory device and its reading fail analyzing method are provided, which efficiently restore the bit error by accurately finding the reason of the reading fail in reading. A semiconductor memory device(10) comprises the nonvolatile memory(100) and memory controller(200). The nonvolatile memory stores data. The memory controller controls the operation of the nonvolatile memory. The memory controller finds out reading fail reason due to the charge leakage through the error correcting code analysis. The reason of the reading fail due to soft-program is found out by the memory controller through the change of the selection read voltage.