A jam latch device for a data node includes a feed forward inverter having an input coupled to the data node; a feedback inverter having an input connected to an output of the feed forward inverter with an output of the feedback inverter connected to the data node; an isolation device that selectively decouples the feedback inverter from a power supply rail, the isolation device controlled by a clock signal of a reset device that resets the data node to a first logic state such that decoupling of the feedback inverter from the power supply rail coincides with resetting the data node to the first logic state; and a margin test device that selectively increases pull down strength of the feedback inverter.