A static memory cell, composed of cross-coupled MOS transistors having a relatively
high threshold voltage, is equipped with MOS transistors for controlling the power
supply line voltage of the memory cell. To permit the voltage difference between
two data storage nodes in the inactivated memory cell to exceed the voltage difference
between the two nodes when write data is applied from a data line pair DL and /DL
to the two nodes in the activated memory cell, the power supply line voltage control
transistors are turned on to apply a high voltage VCH to the power supply lines
after the word line voltage is turned off. The data holding voltage in the memory
cell can be activated to a high voltage independent of the data line voltage, and
the data holding voltage can be dynamically set so that read and write operations
can be performed at high speed with low power consumption.
