Multi-level read after heating event in non-volatile storage

Abstract

Technology is disclosed herein for operating a non-volatile memory system following a heating event such as an Infrared (IR) reflow process. The memory system is pre-loaded with data that is stored at multiple bits per memory cell. After the heating event, the memory system calibrates the read reference levels for reading the memory cells at multiple bits per memory cell. However, prior to calibrating the read reference levels, the memory system stabilizes one or more conditions in the memory system, which allows the new read reference levels to be accurately calibrated. The memory system may stabilizes threshold voltage of memory cells and/or word line voltages, for example. In one aspect, a dummy read is performed to stabilize one or more conditions of the memory system. Hence, the read reference levels may be accurately calibrated.