Semiconductor integrated circuit device

A semiconductor integrated circuit device which is provided with a main memory unit and an auxiliary memory unit and which is capable of conducting bidirectional data transfer via data transfer bus lines provided between said main memory unit and said auxiliary memory unit, wherein are provided:

• sense amplifier circuits provided within said main memory unit,
• a sense amplifier unit control circuit for controlling said sense amplifier circuits, and
• switch means for electrically connecting said sense amplifier circuits and main memory unit memory cells within said main memory unit;
• and wherein, after data transferred from said main memory unit to said auxiliary memory unit are incorporated into said sense amplifier circuits, said sense amplifier unit control circuit controls said switch means and electrically disconnects said sense amplifier circuits from said main memory unit memory cells, and data are transferred from said main memory unit to said auxiliary memory unit in this disconnected state.