An impedance calibration circuit includes a first code generation circuit connected to a first reference resistor, and configured to generate a first code for forming a resistance based on the first reference resistor, by using the first reference resistor; a second code generation circuit configured to form a resistance of a second reference resistor less than the resistance of the first reference resistor, based on the first code, and generate a second code by using the second reference resistor; and a target impedance code generation circuit configured to generate a target impedance code based on the first code, the second code, and a target impedance value, and form an impedance having the target impedance value in a termination driver connected to the impedance calibration circuit, based on the target impedance code.

Disclosed are a memory interface circuit including an output impedance monitor, which is capable of monitoring and calibrating an output impedance of a driving circuit in real time, and a method of calibrating the output impedance. The memory interface circuit includes a control circuit that outputs a digital transmission signal, a driving circuit that outputs an output signal, based on the digital transmission signal, an output impedance monitor that outputs a pull-up monitoring signal or a pull-down monitoring signal, based on the digital transmission signal and the output signal, and an output impedance calibrator that outputs an impedance monitoring signal, based on the pull-up monitoring signal or the pull-down monitoring signal, and wherein the driving circuit calibrates output impedance based on the impedance monitoring signal.

Apparatus comprises source circuitry to provide data items; buffer circuitry having a set of buffer entries to hold one or more data items, provided by the source circuitry, for delivery to one or more destinations within a respective delivery latency, in which a buffer entry holding an initial data item becomes available to hold another data item in response to delivery of the initial data item to its respective destination; and control circuitry to control acceptance of data items from the source circuitry for holding by the buffer circuitry, the control circuitry being configured to control the buffer circuitry to accept a given data item when: (i) a buffer entry is available to hold the given data item and (ii) the delivery latency of data items including the given data item held by the buffer circuitry is such that at least a threshold number of buffer entries may be made available within no more than a threshold availability period.

The present disclosure describes systems, apparatuses, and methods for implementing a logic gate circuit structure for operating one or more Boolean functions. Instead of stacking transistors in series to accommodate an increased number of inputs, a parallel configuration is presented that significantly reduces the cascaded number of transistors and the total number of transistors for the same functionality.

A circuit stacking multiple asynchronous circuit components, specifically Multi-Threshold NULL Convention Logic (MTNCL) circuit components, with an overall power supply equal to the multiples of the original VDD.

A data retention circuit includes a power switch, a first inverter and a second inverter. The power switch has a first connection terminal coupled to a power voltage, and a second connection terminal coupled to the first power terminal and a second power terminal of a second inverter. The second input terminal and the second output terminal of the second inverter are coupled to the first output terminal and the first input terminal of the first inverter, respectively. In a sleep mode, the power switch and the transistor are turned off, a first leakage current flows between the first connection terminal and the second connection terminal, a second leakage current flows between the first power terminal and the first output terminal, and the first and the second leakage currents form a steady-state voltage, higher than or equal to a data retention voltage, on a second connection terminal.

A data retention circuit includes a power switch, a first inverter and a second inverter. The power switch has a first connection terminal coupled to a power voltage, and a second connection terminal coupled to the first power terminal and a second power terminal of a second inverter. The second input terminal and the second output terminal of the second inverter are coupled to the first output terminal and the first input terminal of the first inverter, respectively. In a sleep mode, the power switch and the transistor are turned off, a first leakage current flows between the first connection terminal and the second connection terminal, a second leakage current flows between the first power terminal and the first output terminal, and the first and the second leakage currents form a steady-state voltage, higher than or equal to a data retention voltage, on a second connection terminal.

Methods and apparatus relating to an adaptive multibit bus for energy optimization are described. In an embodiment, a 1-bit interconnect of a processor is caused to select between a plurality of operational modes. The plurality of operational modes comprises a first mode and a second mode. The first mode causes transmission of a single bit over the 1-bit interconnect at a first frequency and the second mode causes transmission of a plurality of bits over the 1-bit interconnect at a second frequency based at least in part on a determination that an operating voltage of the 1-bit interconnect is at a high voltage level and that the second frequency is lower than the first frequency. Other embodiments are also disclosed and claimed.

Apparatuses, systems, and methods for memory initiated calibration. The memory includes a termination circuit with a tunable resistor and a calibration detection circuit with a replica tunable resistor. The calibration detection circuit measures a resistance of the replica tunable resistor and provides a calibration request signal if the resistance is outside a tolerance. Responsive to the calibration request signal, a controller of the memory schedules the memory for a calibration operation.

Methods and apparatus relating to an adaptive multibit bus for energy optimization are described. In an embodiment, a 1-bit interconnect of a processor is caused to select between a plurality of operational modes. The plurality of operational modes comprises a first mode and a second mode. The first mode causes transmission of a single bit over the 1-bit interconnect at a first frequency and the second mode causes transmission of a plurality of bits over the 1-bit interconnect at a second frequency based at least in part on a determination that an operating voltage of the 1-bit interconnect is at a high voltage level and that the second frequency is lower than the first frequency. Other embodiments are also disclosed and claimed.