Abstract: One interface chip and a plurality of core chips are electrically connected via a plurality of through silicon vias. A data signal of a driver circuit is input into the core chip via any one of the through silicon vias. An output switching circuit activates any one of tri-state inverters and selects one of the through silicon vias. The tri-state inverters amplify the data signal and transmit it to the through silicon via. Similarly, an input switching circuit activates any one of tri-state inverters. These tri-state inverters also amplify the data signal transmitted from the through silicon via and supply it to the receiver circuit.

Abstract: To include a first replica buffer that has substantially the same circuit configuration as a pull-up circuit which constitutes an output buffer and a second replica buffer that has substantially the same circuit configuration as a pull-down circuit which constitutes the output buffer. When a first calibration command ZQCS is issued, either a control signal ACT1 or ACT2 is activated, and a calibration operation is performed for either the first replica buffer or the second replica buffer. When a second calibration command ZQCL is issued, both of the control signals ACT1, ACT2 are activated and the calibration operation is performed for both the first replica buffer and the second replica buffer.

Abstract: A ZQ calibration command is internally generated from an external command different from a ZQ calibration command so as to automatically perform an additional ZQ calibration operation. A command interval between an inputted command and a next command is effectively employed to obtain a ZQ calibration period. The external command different from the ZQ calibration command is preferably a self-refreshed command. The addition of the ZQ calibration operation shortens intervals between ZQ calibration operations. Thus, it is possible to obtain a ZQ calibration circuit capable of performing a ZQ calibration operation more accurately.

Abstract: A calibration circuit includes replica buffers that have a substantially same circuit configuration as at least a part of an output buffer, an oscillator circuit that generates an internal clock in response to issuance of a calibration command, and a control circuit that controls an impedance of the replica buffers in synchronization with the internal clock. According to the present invention, because a calibration operation that does not depend on an external clock is performed, even when a frequency of the external clock is changed according to an operation mode or the like, it is possible to maintain a constant period of time given to a single adjustment step or a constant time required for a series of calibration operations.

Abstract: To include a first replica buffer that has substantially the same circuit configuration as a pull-up circuit which constitutes an output buffer and a second replica buffer that has substantially the same circuit configuration as a pull-down circuit which constitutes the output buffer. When a first calibration command ZQCS is issued, either a control signal ACT1 or ACT2 is activated, and a calibration operation is performed for either the first replica buffer or the second replica buffer. When a second calibration command ZQCL is issued, both of the control signals ACT1, ACT2 are activated and the calibration operation is performed for both the first replica buffer and the second replica buffer.

Abstract: Impedance adjusting transistors are once inactivated on every occasion of changing an impedance adjusting code. After restoring the potential to an initially set potential by once inactivating the impedance adjusting transistors, the state of the transistors is switched according to the impedance adjusting code. By starting the potential from the initially set potential at the time of switching the state of the transistors, no switching noise is generated. Since no switching noise is generated, a comparator always carries out stable comparison and judgment and thus there is obtained a calibration circuit that ensures stable outputs.

Abstract: A semiconductor device includes a power-supply control portion and a latch portion. The power-supply control portion supplies power to an internal circuit in response to an input signal synchronized with rising of clock. The latch portion latches the input signal in synchronization with falling of the clock and supplies the latched input signal to the internal circuit.

Abstract: A semiconductor storage device includes: an input buffer that receives address data and command data; a first through-latch-type latch circuit that latches the command data in synchronism with a rising edge of a clock signal; and a second through-latch-type latch circuit that latches the address data in synchronism with a falling edge of the clock signal.

Abstract: A fuse latch circuit starts a precharge operation for reading out a state of a fuse element when receiving an external command which is a command to reset an operation mode register (MRS reset command) after power-on, and reads out and latches the state of the fuse element after completion of the precharge operation.

Abstract: To include a first replica buffer that has substantially the same circuit configuration as a pull-up circuit which constitutes an output buffer and a second replica buffer that has substantially the same circuit configuration as a pull-down circuit which constitutes the output buffer. When a first calibration command ZQCS is issued, either a control signal ACT1 or ACT2 is activated, and a calibration operation is performed for either the first replica buffer or the second replica buffer. When a second calibration command ZQCL is issued, both of the control signals ACT1, ACT2 are activated and the calibration operation is performed for both the first replica buffer and the second replica buffer.

Abstract: AZQ calibration command internally generated from an external command different from a ZQ calbration command so as to automatically perform an additional ZQ calibration operation. A command interval between an imputted command and a next command is effectively employed to obtain a ZQ calibration period. The external command different from the ZQ calibration command is preferably a self-refreshed command. The addition of the ZQ calibration operation shortens intervals between ZQ calibration operations. Thus, it is possible to obtain a ZQ calibration circuit capable of performing a ZQ calibration operation more accurately.

Abstract: Impedance adjusting transistors are once inactivated on every occasion of changing an impedance adjusting code. After restoring the potential to an initially set potential by once inactivating the impedance adjusting transistors, the state of the transistors is switched according to the impedance adjusting code. By starting the potential from the initially set potential at the time of switching the state of the transistors, no switching noise is generated. Since no switching noise is generated, a comparator always carries out stable comparison and judgment and thus there is obtained a calibration circuit that ensures stable outputs.