In one embodiment, a device includes a hardware clock to maintain a clock value, a hardware counter to maintain an estimation of a dynamic error bound of the clock value, and a clock controller to intermittently discipline the hardware clock responsively to a remote clock, advance the hardware counter at a rate responsively to a clock drift, and adjust the hardware counter responsively to the hardware clock being disciplined.

An electronic control unit (ECU) includes a processor, a Controller Area Network (CAN) controller, clock gating logic, and security gating logic. The CAN controller having a status and configured to receive data and control signals from the processor, and a clock signal, package the data to create a CAN protocol frame held in at least one transmit buffer, and shift the CAN protocol frame to a CAN transceiver that is configured to transmit the CAN protocol frame to a CAN bus. The security gating logic configured to, in response to the status of the CAN controller being active, inhibit disabling the clock signal.

An electronic control unit (ECU) includes a processor, a Controller Area Network (CAN) controller, clock gating logic, and security gating logic. The CAN controller having a status and configured to receive data and control signals from the processor, and a clock signal, package the data to create a CAN protocol frame held in at least one transmit buffer, and shift the CAN protocol frame to a CAN transceiver that is configured to transmit the CAN protocol frame to a CAN bus. The security gating logic configured to, in response to the status of the CAN controller being active, inhibit disabling the clock signal.

Systems and methods in which devices synchronize their clocks for purposes of data transmission are described. Particularly, the disclosed systems and methods provide detection and mitigation of interference by malicious (or non-malicious) wireless devices with communication of time synchronized data over wireless networks. Systems and methods are provided where times statistics related to multiple instances of wireless time synchronization are collected and collated. Devices in the system can discipline their internal clocks based on the collated time statistics.

Systems and methods in which devices synchronize their clocks for purposes of data transmission are described. Particularly, the disclosed systems and methods provide detection and mitigation of interference by malicious (or non-malicious) wireless devices with communication of time synchronized data over wireless networks. Systems and methods are provided where times statistics related to multiple instances of wireless time synchronization are collected and collated. Devices in the system can discipline their internal clocks based on the collated time statistics.

A master clock signal for an image capture device and a light emission device is accessed. The master clock signal is divided to generate a high frequency clock signal. A frame timer is used to measure a frame time of the image capture device based on cycles of the high frequency clock signal. Based on an exposure timing signal from the image capture device, estimating an exposure start time for the image capture device; is estimated. Based on the estimated starting time, the light emission device begins emission of a positional tracking pattern at the estimated starting time and for a duration determined by the measured frame time of the image capture device.

A master clock signal for an image capture device and a light emission device is accessed. The master clock signal is divided to generate a high frequency clock signal. A frame timer is used to measure a frame time of the image capture device based on cycles of the high frequency clock signal. Based on an exposure timing signal from the image capture device, estimating an exposure start time for the image capture device; is estimated. Based on the estimated starting time, the light emission device begins emission of a positional tracking pattern at the estimated starting time and for a duration determined by the measured frame time of the image capture device.

A clock calibration method and apparatus is provided, where the method includes a terminal device uses first timing information, adjusts second timing information of the terminal device based on reference timing information, and when determining that a first condition is met, switches from using the first timing information to using the second timing information. The first timing information is primary timing information, the second timing information is standby timing information, and the first condition includes that: the first timing information is different from the reference timing information, and the second timing information is the same as the reference timing information; or the first timing information is different from the second timing information; or the first timing information is different from the reference timing information.

A clock calibration method and apparatus is provided, where the method includes a terminal device uses first timing information, adjusts second timing information of the terminal device based on reference timing information, and when determining that a first condition is met, switches from using the first timing information to using the second timing information. The first timing information is primary timing information, the second timing information is standby timing information, and the first condition includes that: the first timing information is different from the reference timing information, and the second timing information is the same as the reference timing information; or the first timing information is different from the second timing information; or the first timing information is different from the reference timing information.

A control system for factory automation includes a first unit and a second unit that exchange data with each other, and a synchronization module that synchronizes a control counter included in the first unit and a control counter included in the second unit using a clock. Each of the units includes an information storage that stores information on conversion for calculating a time from a counter value of the counter of the unit, the information being shared between the units.