Real-time-calibration circuit for multiple CPUS

摘要

A real-time-calibration circuit for multiple CPUs includes the CPUs for communication, for control and for acting as a panel board. The CPUs each have a real-time clock built therein. The CPU for communication is connected with an external real-time clock, and only the external real-time clock is connected with a battery. Through the CPU for communication, a standard time is obtained from an external network and provided to the external real-time clock for time calibration. Then a calibration value generated from the time calibration is fed back to the CPU for communication to be used by the real-time clock of the CPU for communication and the real-time clocks of the other CPUs, so as to prevent the CPUs from interfering communication during time calibration, and reduce the need of power and of batteries, thereby saving energy and costs and being friendly to the environment.

主权项

1. A real-time-calibration circuit for multiple CPUs, the real-time-calibration circuit comprising:
an external real-time clock, being connected with and alternatively powered by a battery; a first CPU acting for communication when connected with an external network for communication, wherein the first CPU is connected with the external real-time clock and includes a first real-time clock built therein; a second CPU acting for control, wherein the second CPU is connected with the first CPU and includes a second real-time clock built therein; and a third CPU acting as a panel board, wherein the third CPU is connected with the first CPU and includes a third real-time clock built therein; whereby, after the first CPU obtains a standard time from the external network and sends the standard time to the external real-time clock for time calibration, the external real-time clock sends a calibration value back to the first CPU so that the first CPU performs time calibration on the first real-time clock built therein, and sends the calibration value to the second real-time clock and the third real-time clock for time calibration.