US Patent 7627065 Generating a clock crossing signal based on clock ratios

A multiple clock domain system. A system comprises two clock domains which receive a source clock signal. The first domain includes a first clock signal with a first frequency and the second domain includes a second clock signal with a second frequency. A ratio of the first frequency to the second frequency is N:M. The first domain is configured to initialize a count to N, if N is less than 2*M; and initialize the count to M, if N is not less than 2*M. Subsequently, on each cycle of the first clock signal, the first domain adds (M-N) to the count and asserts a sample enable signal, if the count is greater than or equal to N; and adds a value equal to M to the count and negates the sample enable signal, if the count is not greater than or equal to N.