Abstract: A hybrid memory device is provided. The hybrid memory device includes a DRAM, a non-volatile memory and a control circuit. The control circuit selects one of output data of the DRAM and output data of the non-volatile memory according to a mode selecting signal and output the selected data. The control circuit outputs data requested to be output from the DRAM when the data requested to be output is in the DRAM, and may output the data requested to be output from the non-volatile memory when the data requested to be output is in the non-volatile memory. Accordingly, the hybrid memory device has a high speed in a read and write operation, and has low power consumption.

Abstract: A memory system and a refresh control method thereof are provided. The memory system includes a semiconductor memory device including a plurality of memory cells and a memory controller configured to generate a special command for searching for refresh information stored in the semiconductor memory device and to control a refresh operation of the semiconductor memory device. The semiconductor memory device is configured to output the refresh information to the memory controller in response to the special command generated by the memory controller.

Abstract: A hybrid memory device is provided. The hybrid memory device includes a DRAM, a non-volatile memory and a control circuit. The control circuit selects one of output data of the DRAM and output data of the non-volatile memory according to a mode selecting signal and output the selected data. The control circuit outputs data requested to be output from the DRAM when the data requested to be output is in the DRAM, and may output the data requested to be output from the non-volatile memory when the data requested to be output is in the non-volatile memory. Accordingly, the hybrid memory device has a high speed in a read and write operation, and has low power consumption.

Abstract: A memory system and a refresh control method thereof are provided. The memory system includes a semiconductor memory device including a plurality of memory cells and a memory controller configured to generate a special command for searching for refresh information stored in the semiconductor memory device and to control a refresh operation of the semiconductor memory device. The semiconductor memory device is configured to output the refresh information to the memory controller in response to the special command generated by the memory controller.

Abstract: A time delay compensation circuit comprises delay cells having various unit time delays. A delay-locked loop, a type of the time delay compensation circuit, includes a phase detector, a delay line, and a filter unit. The phase detector compares the phase of the external clock signal with that of the feedback clock signal and outputs a phase difference as an error control signal. The delay line includes a plurality of delay cells having various unit time delays. The number of delay cells is adjusted in response to a predetermined shift signal. The delay line receives the external clock signal and outputs an output clock signal, which is obtained by controlling the phase of the external clock signal. The filter unit generates the shift signal, which selects the number of delay cells in the delay line, in response to the error control signal.

Abstract: A delay-locked loop includes a phase detector, a delay line, and a filter unit. The phase detector compares the phase of the external clock signal with that of the feedback clock signal and outputs a phase difference as an error control signal. The delay line includes delay cells having various unit time delays. The number of delay cells is adjusted in response to a shift signal. The delay line receives the external clock signal and outputs an output clock signal. The filter unit generates the shift signal in response to the error control signal. In the delay-locked loop, the front delay cells, which compensate for a delay of an external clock signal having a high frequency, have short unit time delays. The rear delay cells, which compensate for a delay of the external clock signal having a low frequency, have long unit time delays.

Abstract: A data output driver of a semiconductor memory device can minimize a difference in slew rate of an output signal according to a selected bit organization. The data output driver includes a pull-up driver and a pull-down driver. The pull-up driver pulls up an output terminal and the pull-down driver pulls down the output terminal. In particular, current driving capabilities of the pull-up driver and/or the pull-down driver are changed in response to bit organization information signals of the semiconductor memory device.

Abstract: Delay-locked loop integrated circuits include a duty cycle correction circuit. This duty cycle correction circuit generates at least one output clock signal having a substantially uniform duty cycle in response to at least one input clock signal having a non-uniform duty cycle. The duty cycle correction circuit is also responsive to a standby control signal that synchronizes timing of power-saving duty cycle update operations within the duty cycle correction circuit. These update operations reset the set point of the correction circuit.

Abstract: A delay locked loop (DLL) circuit having a duty cycle corrector (DCC) that has a broad range of duty cycle correction, consumes only a small amount of power, has few restrictions on operating frequency, and improves the characteristics of a memory device is described. The delay locked loop circuit includes an additional loop for duty cycle correction as well as loops for controlling a rising edge and a falling edge of output signals. Thus, the delay locked loop circuit can internally correct the duty cycle without the use of a phase blender.

Abstract: Delay-locked loop integrated circuits include a duty cycle correction circuit. This duty cycle correction circuit generates at least one output clock signal having a substantially uniform duty cycle in response to at least one input clock signal having a non-uniform duty cycle. The duty cycle correction circuit is also responsive to a standby control signal that synchronizes timing of power-saving duty cycle update operations within the duty cycle correction circuit. These update operations reset the set point of the correction circuit.

Abstract: A data output driver of a semiconductor memory device can minimize a difference in slew rate of an output signal according to a selected bit organization. The data output driver includes a pull-up driver and a pull-down driver. The pull-up driver pulls up an output terminal and the pull-down driver pulls down the output terminal. In particular, current driving capabilities of the pull-up driver and/or the pull-down driver are changed in response to bit organization information signals of the semiconductor memory device.

Abstract: A time delay compensation circuit comprises delay cells having various unit time delays. A delay-locked loop, a type of the time delay compensation circuit, includes a phase detector, a delay line, and a filter unit. The phase detector compares the phase of the external clock signal with that of the feedback clock signal and outputs a phase difference as an error control signal. The delay line includes a plurality of delay cells having various unit time delays. The number of delay cells is adjusted in response to a predetermined shift signal. The delay line receives the external clock signal and outputs an output clock signal, which is obtained by controlling the phase of the external clock signal. The filter unit generates the shift signal, which selects the number of delay cells in the delay line, in response to the error control signal.

Abstract: A delay locked loop (DLL) circuit having a duty cycle corrector (DCC) that has a broad range of duty cycle correction, consumes only a small amount of power, has few restrictions on operating frequency, and improves the characteristics of a memory device is described. The delay locked loop circuit includes an additional loop for duty cycle correction as well as loops for controlling a rising edge and a falling edge of output signals. Thus, the delay locked loop circuit can internally correct the duty cycle without the use of a phase blender.

Abstract: A synchronous dynamic random access memory (SDRAM) semiconductor device is provided. The SDRAM has a write-interrupt-write function and includes a first memory block for storing data, a first sense amplifier for sensing the data stored in the first memory block, first and second groups of input/output lines, connected to the first sense amplifier, and a write-interrupt-write signal generating portion for receiving an externally input write signal and an internal clock signal to generate a write-interrupt-write signal, and for providing the write-interrupt-write signal to the first sense amplifier.