A pseudo static random access memory including a plurality of memory chips and an information storing device is provided. The memory chips transmit a plurality of read/write data strobe signals to a memory controller by using a same bus. Regardless of whether a self refresh collision occurs in the memory chips, when the memory chips perform a read operation, read latency of the memory chips is set to be a fixed period that self refresh is allowed to be completed. The fixed period is greater than initial latency. The information storing device is configured to store information which defines the fixed period. The read/write data strobe signal indicates whether the self refresh collision occurs in the memory chips, and a level of the read/write data strobe signals is constant during the read latency. A method for operating a pseudo static random access memory is also provided.

A method and memory device of controlling a plurality of low power states are provided. The method includes: entering a low power mode state, in which memory cell rows of the memory device are refreshed and power consumption is lower than in a self-refresh mode state, in response to a low power state entry command; and exiting the low power mode state based on a low power mode exit latency time that is set in a mode register of the memory device or at least one of an alarm signal and a low power mode exit command.

A calibration circuit includes first and second pull-up units each receiving a pull-up code and connected between a pad connected with an external resistor and a first power supply voltage, a pull-down unit connected between the pad and a second power supply voltage and receiving a pull-down code, a comparator comparing a first voltage with a reference voltage and then compare a second voltage with the reference voltage, a first digital filter adjusting the pull-up code based on a first comparison result of the first voltage with the reference voltage, and a second digital filter adjusting the pull-down code based on a second comparison result of the second voltage with the reference voltage.

Disclosed herein is an apparatus that includes a first semiconductor chip including a memory cell array having a volatile memory cell and an access control circuit configured to perform a refresh operation on the volatile memory cell, and a second semiconductor chip including a power generator configured to supply a first power supply voltage to the first semiconductor chip. The access control circuit is configured to activate a first enable signal during the refresh operation. The second semiconductor chip is configured to change a capability of the power generator based on the first enable signal.

A power control circuit includes a power control signal generation circuit configured to generate a voltage control signal according to a deep sleep command for operating a semiconductor apparatus in a deep sleep mode; a voltage divider circuit having a division ratio that is changed according to the voltage control signal, and configured to generate a divided voltage by dividing an internal voltage at the changed division ratio; a comparator configured to generate a detection signal by comparing a reference voltage to the divided voltage; an oscillator configured to generate an oscillation signal according to the detection signal; and a pump configured to generate the internal voltage according to the oscillation signal.

The present embodiments provide a system that supports self-refreshing operations in a memory device. During operation, the system transitions the memory device from an auto-refresh state, wherein a memory controller controls refreshing operations for the memory device, to a self-refresh state, wherein the memory device controls the refreshing operations. While the memory device is in the self-refresh state, the system sends progress information for the refreshing operations from the memory device to the memory controller. Next, upon returning from the self-refresh state to the auto-refresh state, the system uses the progress information received from the memory device to control the sequencing of subsequent operations by the memory controller.

An apparatus may include a semiconductor device that includes an internal clock circuit configured to receive an internal clock signal and to provide a local clock signal based on the internal clock signal. The internal clock circuit comprises a clock synchronizer configured to, in response to receipt of a command to exit a self-refresh mode, disable provision of the local clock signal by a number of cycles of the internal clock signal.

A semiconductor device may be provided. The semiconductor device may include a power-down signal generation circuit and a refresh signal generation circuit. The power-down signal generation circuit may be configured to generate a power-down signal which is enabled during a power-down operation period based on a multi-operation signal that is generated by decoding commands. The refresh signal generation circuit may be configured to generate a refresh signal which is enabled during a refresh operation period based on the multi-operation signal and an operation selection signal.

In one embodiment, an apparatus comprises a processor core and a power control unit. The power control unit is to identify the occurrence of a power loss from a primary power source, instruct the I/O controller to block further write requests from the one or more I/O devices and to send at least one pending write request stored by the I/O controller to the memory controller, and instruct the memory controller to complete at least one pending write request stored by the memory controller and to cause the memory to be placed into a self-refresh mode.

Disclosed herein is an apparatus that includes a memory cell array including a plurality of memory cells, a first counter circuit configured to periodically update a count value during a first operation mode, a burst clock generator configured to successively generate a burst pulse predetermined times when the count value indicates a predetermined value, and a row address control circuit configured to perform a refresh operation on the memory cell array in response to the burst pulse.