A high-speed serial interface is provided. In one aspect, the high-speed serial interface uses three phase modulation for jointly encoding data and clock information. Accordingly, the need for de-skewing circuitry at the receiving end of the interface is eliminated, resulting in reduced link start-up time and improved link efficiency and power consumption. In one embodiment, the high-speed serial interface uses fewer signal conductors than conventional systems having separate conductors for data and clock information. In another embodiment, the serial interface allows for data to be transmitted at any speed without the receiving end having prior knowledge of the transmission data rate. In another aspect, the high-speed serial interface uses polarity encoded three phase modulation for jointly encoding data and clock information. This further increases the link capacity of the serial interface by allowing for more than one bit to be transmitted in any single baud interval.

System, methods and apparatus are described that facilitate transmission of data, particularly between two devices within an electronic apparatus. Information is transmitted in N-phase polarity encoded symbols. Data is encoded in multi-bit symbols, and the multi-bit symbols are transmitted on a plurality of connectors. The multi-bit symbols may be transmitted by mapping the symbols to a sequence of states of the plurality of connectors, and driving the connectors in accordance with the sequence of states. The timing of the sequence of states is determinable at a receiver at each transition between sequential states. The state of each connector may be defined by polarity and direction of rotation of a multi-phase signal transmitted on the each connector.

Described are on-die termination (ODT) systems and methods that facilitate high-speed communication between a driver die and a receiver die interconnected via one or more signal transmission lines. An ODT control system in accordance with one embodiment calibrates and maintains termination resistances and drive currents to produce optimal output swing voltages. Comparison circuitry employed to calibrate the reference resistance is also used to calibrate the drive current. Termination elements in some embodiments are divided into two adjustable resistive portions, both of which are designed to minimize capacitive loading. One portion is optimized to produce a relatively high range of adjustment, while the other is optimized for fine-tuning and glitch-free switching.

The present invention is directed to communication systems and electrical circuits. According to an embodiment, the present invention provides a termination circuit that includes an inductor network. The inductor network is coupled to a termination resistor and a capacitor network, which includes a first capacitor and a second capacitor. The termination resistor, the first capacitor, and the second capacitor are adjustable, and they affect attenuation of the termination circuit. There are other embodiments as well.

A high-speed voltage clamping circuit includes p-type field effect transistor (PFET) biasing circuit, an n-type field effect transistor (NFET) biasing circuit, and a field effect transistor (FET) clamp circuit. The PFET biasing circuit is configured to generate a PFET biasing voltage. The NFET biasing circuit is configured to generate a NFET biasing voltage. The FET clamp circuit is in signal communication with the PFET biasing circuit and the NFET biasing circuit. The PFET biasing circuit controls operation of the clamping circuit in response to a voltage overshoot event and the NFET biasing circuit controls operation of the clamping circuit in response to a voltage undershoot event.

A multi-chip module (MCM includes a substrate and first and second integrated circuit chips disposed on the substrate. The second IC chip includes transceiver circuitry configured to communicate with the first IC chip. The transceiver circuitry includes transmit circuitry having an inverter circuit to generate a first signal for transmission to the first IC chip along a signaling link. The signaling link includes a line termination impedance. Receiver circuitry includes a receiver circuit to receive a second signal from the first IC chip along the signaling link concurrently with transmission of the first signal along the signaling link. Hybrid circuitry is coupled to the transmit circuitry and to the receiver circuitry. The hybrid circuitry is configured to cancel a received component of the first signal. The hybrid circuitry includes a replica termination impedance that is configured in an open state.

A redriver chip includes a controller and a plurality of circuits coupled to the channel. The controller adjusts a set of parameters of the plurality of circuits to have first values during a first mode of operation and second values during a second mode of operation. The first values generate a first level of power consumption during the first mode of operation, and the second values generate a second level of power consumption during the second mode of operation. The first level of power consumption is lower than the second level of power consumption, and the first mode of operation corresponding to a low-power mode of the redriver chip.

A high-speed voltage clamping circuit includes p-type field effect transistor (PFET) biasing circuit, an n-type field effect transistor (NFET) biasing circuit, and a field effect transistor (FET) clamp circuit. The PFET biasing circuit is configured to generate a PFET biasing voltage. The NFET biasing circuit is configured to generate a NFET biasing voltage. The FET clamp circuit is in signal communication with the PFET biasing circuit and the NFET biasing circuit. The PFET biasing circuit controls operation of the clamping circuit in response to a voltage overshoot event and the NFET biasing circuit controls operation of the clamping circuit in response to a voltage undershoot event.

A device receives an analog voltage signal over a single physical electrical connection. The analog voltage signal can be converted into a digital value which can then be correlated to (i) an indication of a connection state of the primary device, and (ii) information about another device (or set of devices) which is connected to the device.

A memory controller and/or memory device control termination of a communication link in order to achieve power savings while reducing or eliminating unwanted reflections in the channel. Following transmission of data over the communication channel, termination is left enabled for a programmable time period beginning immediately following completion of the transmission. The time period is sufficiently long to allow the unwanted reflections to be absorbed by the termination. Following the time period, the termination is disabled for power savings.