| 摘要 |
PURPOSE:To make it possible to use a semiconductor storage device also as a RAM and a variable length shift register by adding an address counter, a coincidence detecting circuit, an address selector, an external clock terminal for shifting up an address counter, and a mode switching terminal to reference RAM constitution. CONSTITUTION:The address counter 2, the coincidence detecting circuit 3, the address selector 9, the external clock terminal for shifting up the address counter 2, and the mode switching terminal are added to the reference RAM constitution. When an address signal is impressed on an external address terminal 10 in a mode II for turning the mode switching terminal VSR to '0', the constitution is driven as a RAM, and when a clock signal is impressed on the external clock terminal in a mode I for turning the terminal VSR to '1', the device is driven as a shift register with 1-2<m> optional length corresponding to 1-2<m> optional binary values set up in the terminal 10. Consequently, a semiconductor storage device having high using efficiency can be obtained. |
