OPERATING MODE DETERMINING CIRCUIT OF SEMICONDUCTOR MEMORY DEVICE

摘要

PURPOSE: An operating mode determining circuit is provided to perform a mode select operation through a circuit instead of a metal process or a bonding process. CONSTITUTION: A CAS-before-RAS(CBR) sensing circuit(100) senses a CBR signal from an internal signal(R1, C1), and a RAS only refresh(ROR) sensing circuit(200) senses a ROR signal from the internal signal(R1, C1). An initial cycle sensing circuit(300) senses an initial cycle signal from the internal signal(R1). A latch circuit(400) latches output signals of the CBR sensing circuit(100) and the ROR sensing circuit(200) in response to an output of the initial cycle sensing circuit(300).