US Patent 7861128 Scan element with self scan-mode toggle

A scan element with self scan-mode toggle is described. In an example, the scan element is configured to automatically switch between a capture mode and a scan mode. In the capture mode, data is captured from logic under test. In the scan mode, the captured data is scanned out for testing. The scan elements each include a shift register that serves a dual purpose of providing control for determining when the scan element is to switch from the capture mode and the scan mode, as well as providing a location to store captured data.