An electronic device includes a bus driver and circuitry. The bus driver is coupled to a parallel bus including N data lines. The circuitry is configured to receive a data unit for transmission over the N data lines, to determine a first count indicative of a number of data bits in the data unit having a predefined value, and a second count indicative of a number of inverted data bits relative to corresponding bits in a previously transmitted data unit, to make a decision of whether to invert the data unit based on the first and second counts, depending on whether such inversion is expected to reduce power consumption of transmitting the data unit over the bus, to produce an output data unit by retaining or inverting the data unit based on the decision, and to transmit the output data unit over the data lines via the bus driver.

An information handling system includes resistive short detection circuitry that measures a first amount of power provided by a power supply system, and measures a second amount of power drawn by components. The resistive short detection circuitry compares the first amount of power with the second amount of power. In response to first amount of power being greater than the second amount of power, the resistive short detection circuitry determines that a short exists within the information handling system.

Aspects disclosed in the detailed description include power saving techniques in computing devices. In particular, as data is received by a modem processor in a computing device, the data is held until the expiration of a modem timer. The data is then passed to an application processor in the computing device over a peripheral component interconnect express (PCIe) interconnectivity bus. On receipt of the data from the modem processor, the application processor sends data held by the application processor to the modem processor over the PCIe interconnectivity bus. The application processor also has an uplink timer. If no data is received from the modem processor before expiration of the uplink timer, the application processor sends any collected data to the modem processor at expiration of the uplink timer. However, if data is received from the modem processor, the uplink timer is reset.

In some embodiments, provided are circuits and approaches for responding to wake requests over a data bus such as with a USB interface. An interconnect PHY may be placed into an aggressive power reduction mode and in response to a detected wake request on the bus, respond in a sufficient time by keeping at least a portion of a transmitter data path in the PHY powered on during the reduced power mode and responding to the wake request while the PHY re-boots in the background.

In accordance with an embodiment, an integrated driver circuit includes: a first connection and a second connection configured to be connected to a control chip; at least one bus connection configured to be connected to a bus line; and a control circuit. The control circuit is configured to operate in a first mode or a second mode; to output a reception signal at the second connection in the second mode, where the reception signal represents a bus signal received at the bus connection; to assume a state of low power consumption in the first mode; to change from the first mode to the second mode when a first command is detected at the first connection or at the second connection; and to change from the second mode to the first mode when the bus signal does not indicate any data for a predefined period of time.

An apparatus is provided. The apparatus comprises interface circuitry, machine-readable instructions, and processing circuitry to execute the machine-readable instructions to determine that a first composite link of a plurality of composite PCIe links terminating at the same PCIe root port lacks support for enabling a desired power saving state or an exit latency for the first composite link is above a first latency threshold. The processing circuitry is further configured to determine whether an exit latency for a second composite link of the plurality of composite PCIe links is below a second latency threshold and selectively trigger at least one sub-link of the second composite link to enable the desired power saving state if the exit latency for the second composite link is below the second latency threshold.

A system and method for efficiently transferring data between devices. In various embodiments, a host computing device receives parallel data, encodes the parallel data as a count of pulses as serial data, and conveys the serial data to a peripheral device. The peripheral device decodes the received serial data to determine the parallel data, which is sent to processing logic. The devices send the encoded pluses on a bidirectional line, so the pulses are capable of being sent in both directions. The devices send the encoded pulses on the bidirectional line using a non-zero base voltage level. The devices are capable of using a voltage headroom when conveying encoded pulses between one another. Therefore, a full voltage swing between a ground reference voltage level and a power supply voltage level is not used when conveying the encoded pulses, which reduces power consumption.

Systems, apparatuses, and methods for saving power on a bus interface are described. A system includes a host, a device, and a repeater interposed between the host and the device. While the host and device are in a low-power state, the repeater monitors a first bus to determine if the device has woken up. When the repeater detects a remote wake-up event initiated by the device, the repeater generates an interrupt which is sent to the host. The host responds to the interrupt by initiating a resume wake-up event procedure that assumes the device is still asleep. In this way, the host is able to stay in the low-power state longer while also using a wake-up procedure that does not require the host to be aware of the existence of the repeater.

A chip includes a peripheral component interconnect express (PCIe) switch, a dual-mode device, and a signal transmission control circuit. The PCIe switch includes a first downstream port. The dual-mode device switches between a root complex (RC) mode and an endpoint (EP) mode. The signal transmission control circuit is coupled between the PCIe switch and the dual-mode device. The first downstream port communicates with the dual-mode device operating under the EP mode. The signal transmission control circuit allows an external PCIe device to communicate with the dual-mode device operating under the RC mode.

A method and apparatus for scrambling and descrambling data in a computer system includes transmitting non-scrambled data from a first high speed inter chip (IP) link circuit located on a first chip to a first serializer/deserializer (SERDES) physical (PHY) circuit located on the first chip, the first high speed link IP indicating the data is not scrambled. The received non-scrambled data is scrambled by the first SERDES PHY circuit and transmitted to a second chip. The received scrambled data is descrambled by a second SERDES PHY circuit located on the second chip. The non-scrambled data is transmitted by the second SERDES PHY circuit to a second high speed link IP circuit located on the second chip to a third circuit for further processing or transmission.