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Method and device for keeping accurate time for a hybrid GPS receiver and mobile phone when powered off
Method and device for keeping accurate time for a hybrid GPS receiver and mobile phone when powered off
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机译:断电时为混合gps接收器和手机保持准确时间的方法和装置
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摘要
A hybrid navigation satellite receiver and mobile telephone uses only two crystal oscillators. One that operates a master clock around 27-MHz and that consumes milliwatts of power. The other oscillator consumes only microwatts of power and operates continuously on battery power at about 32-KHz. Only the second, low frequency oscillator is kept running during power "off". On power "restart", a real-time-clock counter is consulted to cause an estimate of the GPS system time to be regenerated and supplied to the GPS-DSP to quicken its initialization. The master clock is GPS-calibrated, and the accurate clock is used to drive NCO's for the mobile telephone part and host CPU.
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