| 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 address change detecting circuit, and an external clock terminal for shifting up the address counter to reference RAM constitution. CONSTITUTION:The address counter 2, the coincidence detecting circuit 3, the address selector 9, the address changing circuit 8, and the external clock terminal for shifting up said address counter 2 are added to the reference RAM constitution, and when the external clock terminal is set up to '0' and an address signal is impressed on an external address terminal 10, the constitution is driven as a RAM. When a clock signal is impressed on the external clock terminal, the device is driven as shift registers with 1-2<m> optional length corresponding to 1-2<m> optional binary values set up on the terminal 10. Consequently, a semiconductor storage device having high using efficiency can be obtained. |
