MASK ROM

摘要

PURPOSE:To make a parasitic capacitance of a bit line constant by connecting a drain electrode of a field effect type transistor (TR) forming a memory cell array to a bit line and writing information depending whether a source electrode of the TR is connected to a power wiring. CONSTITUTION:Drain electrodes of field effect type TRs Q1100-Q1nm forming a memory cell array 11 are connected to bit lines BL0-BLm and the information is written depending whether or not source electrodes of the TRs Q1100-Q1nm are connected to a power wiring 18. The information is written depending whether or not source electrodes of the TRs Q1100-Q1nm are connected to the power wiring 18, then the number of the memory cell TRs Q1100-Q1nm connecting to the bit lines BL0-BLm is constant independently of the storage content. Thus, the parasitic capacitance of the bit lines is made constant independently of the storage content.