Isolated scan paths

A method of isolating scan paths in an integrated circuit to reduce the RC delay associated with the scan paths and reduce power consumption, and to further enhance the capacitive decoupling of the power supply to reduce noise. The scan path can be connected to a data-storage element (latch or flip-flop) by a CMOS transmission gate, a single PMOS or NMOS transistor, or a logic gate (such as a NAND gate). The data-storage element is tested using either a scan-enable line, or the scan clock which is also connected to the data-storage element as an input. When the scan-enable line (or scan clock) is turned on, the scan path is connected to the output of the data-storage element.