Oscillator auto-trimming method and semiconductor device using the method

摘要

An oscillator auto-trimming method is provided. The oscillator auto-trimming method includes receiving, by a subtractor, a first count result and second count result to output a difference between the first count result and the second count result as an offset frequency, receiving, by a divider, the offset frequency to output a divided signal corresponding to a result of dividing the offset frequency by a reference offset frequency output from a micro control unit, and receiving, by the micro control unit, the divided signal and determine whether to change an oscillator frequency.

主权项

1. A semiconductor device having an oscillator auto-trimming function, the semiconductor device comprising:
an oscillator configured to generate an oscillator clock signal; a subtractor configured to receive a first count result and second count result and output a difference between the first count result and the second count result as an offset frequency; a divider configured to receive the offset frequency and output a divided signal corresponding to a result of dividing the offset frequency by a reference offset frequency; and a register configured to receive the divided signal, to change a reference index into a target index by subtracting or adding the divided signal from or to the reference index, and to transmit an oscillator trimming code corresponding to the target index to the oscillator, wherein the first count result is determined by a frequency of a reference clock signal and the second count result is determined by a frequency of the oscillator clock signal.