Utilizing outer counter and timing counter in P87LPC767, the system can measure the Cyc of the output signal. The metrical error is less than 0.0013s and meets the requirement of the measure.

• 利用外部计数器和P87LPC767定时计数器，完成了对气压传感器输出信号周期的准确测量，测量误差在国家气象局规定范围内。