Patent ID: 8416901

Claim:
A method for detecting frequency deviation of a clock, comprising: counting the clock to be detected to acquire current counting information; filtering the current counting information to acquire filtered data; and acquiring the frequency deviation of the clock to be detected from the filtered data, wherein filtering the current counting information comprises: performing a first-order filtering to N based on an equation P n =a·P n-1 +N, wherein n is a number of accumulations, N is n th counting information acquired by counting the clock to be detected by a standard frequency clock, P n-1 is data acquired after n−1 th filtering, P n is data acquired after n th filtering, a is a detection parameter, and O<α<1; wherein acquiring the frequency deviation of the clock to be detected from the filtered data comprises: calculating the frequency deviation of the clock to be detected according to the following equation: Δ ⁢ ⁢ f = ( P n - M 1 - a ) / ( M 1 - a ) = ( 1 - a ) ⁢ P n M - 1 , wherein M is counting information acquired by counting the standard frequency clock, and Δf is the frequency deviation of the clock to be detected.