Patent ID: 8050083
Filing Date: 2011-11-01
Classification: G11C

Abstract:
1. A write method of a phase change memory device, the method comprising: setting a write mode as one of a volatile write mode and a non-volatile write mode; writing data as volatile or non-volatile on a phase change memory cell of the phase change memory device by applying a write pulse corresponding to the write mode, the write pulse provided in the phase change memory cell being determined to be a write reset pulse or a write set pulse in accordance with the data value to be written, wherein writing data includes: wherein, when power is not supplied to the phase change memory device the non-volatile data is retained and the volatile data is not retained; monitoring a capacity of a battery, the battery configured to supply power to the phase change memory device; and rewriting written volatile data as non-volatile data when the capacity of the battery is below a predetermined level.