摘要 |
The problem of undesired power consumption in an oscillator during "stop" periods of a device is addressed by providing the oscillator in apparatus external to the device, the apparatus including a current sensor sensing current in a line between the apparatus and the device, the line communicating an oscillator "clock" signal. If the device enters a "stop" state the current flow during certain half-cycles of the oscillation is relatively low compared to the current flow in the "no-stop" state. In response to the relatively low current, the apparatus halts oscillation. Later, when the device exits the "stop" state, current flow increases in the line, and the apparatus resumes oscillation, thereby resuming the communication of the clock signal to the device. Alternatively the apparatus monitors two oscillator lines by means of an XOR gate, powering down the oscillator when the XOR output goes low and restoring the oscillator when the XOR output goes high. |