| 摘要 |
PROBLEM TO BE SOLVED: To provide a DRAM chip furnished with an inside ODT signal producing circuit capable of changing over the signal from an ODT asynchronous signal to an ODT synchronous signal by taking account of a starting time of a DLL circuit. SOLUTION: In the semiconductor memory chip, by an inside CKE signal producing circuit 610, the delay amount corresponding to a frequency shown by a frequency coping signal and determined by taking account of the stating time of the DLL circuit 100 is added to a clock enable signal and output as an inside clock enable signal, and it is delayed by the ODT latency amount by an ODTL counter 650 and output to a selector 700 as a selection changeover signal. By this procedure, the changeover of signal from the ODT asynchronous signal to the ODT synchronous signal in the period while the ODT signal is asserted, can be instructed to the selector 700 with an appropriate timing. COPYRIGHT: (C)2007,JPO&INPIT
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