A memory system includes a memory controller and a memory module. The memory controller is arranged for selectively generating at least a clock signal and an inverted clock signal. The memory module includes a first termination resistor, a second termination resistor and a switch module, where a first node of the first termination resistor is to receive the clock signal, a second termination resistor, wherein a first node of the second termination resistor is to receive the inverted clock signal, and the switch module is arranged for selectively connecting or disconnecting a second node of the second termination resistor to a second node of the first termination resistor.

A signal transmitting and receiving apparatus including: a first on-die termination circuit connected to a first pin through which a first signal is transmitted or received and, when enabled, the first on-die termination circuit is configured to provide a first termination resistance to a signal line connected to the first pin; a second on-die termination circuit connected to a second pin through which a second signal is transmitted or received and, when enabled, the second on-die termination circuit is configured to provide a second termination resistance to a signal line connected to the second pin; and an on-die termination control circuit configured to independently control an enable time and a disable time of each of the first on-die termination circuit and the second on-die termination circuit.

Apparatuses and methods for identifying memory devices of a semiconductor device sharing an external resistance are disclosed. A memory device of a semiconductor device may be set in an identification mode and provide an identification request to other memory devices that are coupled to a common communication channel. The memory devices that are coupled to the common communication channel may share an external resistance, for example, for calibration of respective programmable termination components of the memory devices. The memory devices that receive the identification request set a respective identification flag which can be read to determine which memory devices share an external resistance with the memory device having the set identification mode.

A radio-frequency switch includes a first field-effect transistor disposed between a first node and a second node, the first field-effect transistor having a source, a drain, a gate, and a body. The switch further includes a coupling path connected between the body of the first field-effect transistor and the gate of the first field-effect transistor, the coupling path including a diode. The switch further includes an adjustable impedance network connected between the body of the first field-effect transistor and a ground reference, the adjustable impedance network being configured to reduce radio-frequency distortion in the first field-effect transistor.

In one example, a device may include a first push-pull driver with a first impedance and a push-pull driver unit with a second push-pull driver having a second impedance. The push-pull driver unit may be in parallel with the first push-pull driver. The device may further include a pulse generating unit to activate the push-pull driver unit for a delay time following an edge transition in an input signal. In one example, the device may have an output impedance that is less than the first impedance when the push-pull driver unit is activated.

Systems, apparatuses, and methods for conveying and receiving information as electrical signals in a computing system are disclosed. A computing system includes multiple transmitters sending singled-ended data signals to multiple receivers. A termination voltage is generated and sent to the multiple receivers. The termination voltage is coupled to each of signal termination circuitry and signal sampling circuitry within each of the multiple receivers. Any change in the termination voltage affects the termination circuitry and affects comparisons performed by the sampling circuitry. Received signals are reconstructed at the receivers using the received signals, the signal termination circuitry and the signal sampling circuitry.

A data output buffer includes a first driver configured to drive a data input/output (I/O) pad according to an input signal and allow data drivability to be controlled according to an impedance calibration code and a second driver configured to perform a de-emphasis operation on the data I/O pad and allow de-emphasis drivability to be controlled according to the impedance calibration code.

A memory interface circuit includes a first variable impedance circuit coupled between a first supply voltage and a pad, and a second variable impedance circuit coupled between a second supply voltage and the pad; wherein when the first supply voltage changes, at least one of the first variable impedance circuit and the second variable impedance circuit is controlled to have different setting in response to the changing of the first supply voltage.

An impedance calibration circuit includes a first code generator, a first code storing circuit, a second code generator and a second code storing circuit. The first code generator generates a pull-up control code obtained from a result of comparing a target output high level (VOH) voltage with a first voltage of a first node. The first code storing circuit stores the pull-up control code when the target VOH voltage becomes the same as the first voltage. The second code generator generates a pull-down control code obtained from a result of comparing the VOH voltage with a second voltage of a second node. The second storing circuit stores the pull-down control code when the target VOH voltage becomes the same as the second voltage. The first code storing circuit and the second code storing circuit store pull-up control code and pull-down control code pairs respectively.

A semiconductor integrated circuit is described. A transmitter-receiver transmits and receives data to and from outside by a first external terminal and transmits a first control signal by a second external terminal. When another data is transmitted after the data is transmitted and when a data transmission interval from a time when the data is transmitted to a time when the another data is transmitted is equal to or smaller than a first threshold, the transmitter-receiver continuously outputs, from the first external terminal, a potential level of about ½ of a potential level obtained by adding a first potential level and a second potential level, during the data transmission interval, and changes the second potential level of the first control signal to the first potential level when the data transmission interval exceeds the first threshold.