Design And Realization Of Real Time Clock Integrated Circuit In Direct Acquisition Receiver

As the imminent need of the satellitic navigation and orientation in modern warfare and the dependence of navigation and orientation in the country’s economy grow each day, navigation and orientation is playing an irreplaceable role in modern society. Nevertheless, the key to navigation P-code capturing and tracking is confirming the initial capture time. The more accurate the initial time is and the shorter the capture time is, the easier the capture process will be. Accordingly, researching and realizing a high accurate real-time clock circuit means a lot to boosting navigation P-code capturing rate.The punctual chip for the satellitic navigation user machine can not only calculate time, but also consist I2 C bus wire, has power managing function and can realize exterior reference time adjusting. The chip is mainly designed from four aspects: circuit structuring, punctual arithmetic optimizing, package customizingand batch debugging. It is designed by module, and finally constructed around “thermo-conductor +ADC+EEPROM+DAC” with compensation. At the same time, the chip designing takes low power and high accuracy chip index into consideration, graudually achieves a high punctual accuracy by repeating optimizing and improving. In the contest, all the performance index of the real-time clock chip of this project meet the requirements of the expectation. And its punctual accuracy reached international advanced level.Pointing at the producting and adjusting process of the thermo compensate punctual chip, we are developing punctual chip batch debugging system to reach the goal of chip automatic debugging, automatic obtaining sampling thermo compensate, automatic storing data and data processing.