Patent 7640124 was granted and assigned to Fujitsu on December, 2009 by the United States Patent and Trademark Office.
In a delay failure test circuit, a delay failure test between two clock domains among a plurality of clock domains having different operation clock rates is performed. The delay failure test circuit inputs, to a first clock domain, a clock signal having only a launch edge for transferring data from the first clock domain to a second clock domain, and to input, to the second clock domain, a clock signal having only a capture edge for capturing the data.