Patent ID: 8255708

Claim:
Universal Serial Bus (USB) device having reduced power consumption, the USB device comprising: a bus clock synchronization module configured to measure a bus clock period, wherein the bus clock period is associated with a communication bus connecting the USB device to a host device; and a power control module configured to: i) determine a first power save time period in which an application module of the USB device is to enter a first power save mode, wherein the application module is configured to perform application-specific functionality of the USB device; ii) determine a second power save time period in which the communication bus is to enter a second power save mode, wherein determining the second power save time period is based on the first power save time period and the bus clock period; iii) send a power save request to the host device, wherein the power save request corresponds to a request for the communication bus to enter the second power save mode for the second power save time period; and iv) cause the USB device to enter a third power save mode of operation in response to a reply to the power save request, including causing the application module to enter the first power save mode for the first power save time period by communicating with the application module via an interface separate from the communication bus.