Patent attributes
A scannable latch incorporates a logic front end that has at least one dynamic logic gate that has a logic tree that perform the normal Boolean logic operation. The dynamic logic gate is combined a scan pull-down logic tree that is coupled to a scan hold latch output and to the dynamic node of the dynamic logic gate. A scan clock and a normal clock determine whether the logic circuitry is in the normal logic mode or in the scan test mode. A static output latch has at least one input that is responsive logic state of a dynamic node. The evaluated state of the dynamic node is set by either the logic tree of the dynamic logic gate or the scan pull-down logic tree of the scan circuitry in response to the logic state of the scan clock or the normal clock.
