1. Technical Field
The present invention relates generally to digital computers; and more particularly to wireless interface devices coupled to digital computers.
2. Related Art
Wireless communication technology has advanced rapidly over the past few years. One of the most promising areas for the use of wireless technology relates to communications between input/output devices and their “host” computers. For example, wireless keyboards and mice now couple via wireless connections to their host computers. These “wireless” input devices are highly desirable since they do not require any hard-wired connections with their host computers. However, the lack of a wired connection also requires that the wireless input devices contain their own power supply, i.e., that they be battery powered. In order to extend the life of their batteries, the wireless input devices often support power saving modes of operation. Some techniques for conserving power, however, can cause degradation in the performance of various system components in the wireless interface.
The various components in a wireless interface device have different operating requirements for the clock signals used for their operation. For example, the analog module typically requires a high quality clock signal with very low phase-noise. The digital module, however, can generally be operated efficiently with a clock signal having a higher phase-noise without serious degradation in performance. Generating a clock signal with the higher quality, low phase-noise characteristics required by an analog module requires more power than is required to generate a clock signal having the quality parameters required for a digital module. If the analog section is not operating, therefore, it is possible to conserve power by generating a clock signal having quality parameters needed only by the digital module. It would be desirable, therefore, to provide a wireless interface device having a power management system capable of conserving power by controlling the clock generator to provide different clock signals that are matched to the specific operational requirements of the system at any time.