Fish & Richardson P.C.
Arithmetic processing unit and driving method thereof
An arithmetic processing unit including an SRAM with low power consumption and performing backup and recovery operation with no burden on circuits. One embodiment is a memory device including a plurality of memory cells. The memory cells include inverters in which capacitors for backing up data are provided. When data of all the memory cells in a region is not rewritten after data is returned from the capacitors to the inverters, data in the region is not transferred from the inverters to the capacitors and the inverters are turned off. When data of at least one of the memory cells in the region is rewritten, data in the region is transferred from the inverters to the capacitors and then power of the inverters are turned off. In this manner, backup is selectively performed to reduce power consumption. Other embodiments are described and claimed.
Semiconductor Energy Laboratory Co., Ltd.
G G
G11C G11C
inventional inventional
Kiyoshi Takahiko Tatsuya
Kato Ishizu Onuki