Boundary-scan bypass circuit for integrated circuit electronic component and circuit boards incorporating such circuits and components

摘要

A method and apparatus for bypassing a boundary-scan cell during functional operation of an electronic component provides a component output signal (such as a data signal) to a boundary-scan bypass circuit during normal functional operation of the electronic component. The component output signal is multiplexed in the bypass circuit with the test result signal that occurs during boundary-scan testing. During functional operation of the electronic component, the component output signal is selected and provided to an output latch that is clocked by a transition of the clock signal of the electronic component. By bypassing the component output signal around the boundary-scan cell during normal operation, the traversing of the multiplexer by the component output signal after the transition of the clock signal of the component is avoided, thereby reducing off-chip delay.