Flexible test site synchronization

A method for performing test site synchronization within automated test equipment (ATE) is presented. The method comprises controlling a plurality of test program controllers (TPCs) using a plurality of bridge controllers (BCs), wherein each TPC can initiate multiple asynchronous events. For an asynchronous event initiated by a TPC, raising a busy flag while the asynchronous event is not yet complete and de-asserting the busy flag when the asynchronous event is complete, wherein the asynchronous event corresponds to a task requiring an indeterminate amount of time. It also comprises generating a busy signal in the first BCs in response to receiving a busy flag from any of the plurality of TPCs, wherein the busy signal remains asserted while any of the plurality of TPCs asserts a busy flag. Finally, it comprises transmitting the busy signal to the plurality of TPCs, wherein the TPCs use the busy signal to synchronize operations.