A design structure for a system for and method of performing high speed memory diagnostics via built-in-self-test (BIST) is disclosed. In particular, a test system includes a tester for testing an integrated circuit that includes a BIST circuit and a test control circuit. The BIST circuit further includes a BIST engine and fail logic for testing an imbedded memory array. The test control circuit includes three binary up/down counters, a variable delay, and a comparator circuit. A method of performing high speed memory diagnostics via BIST includes, but is not limited to, presetting the counters of the test control circuit, presetting the variable delay to a value that is equal to the latency of the fail logic, setting the BIST cycle counter to decrement mode, presetting the variable delay to zero, re-executing the test algorithm and performing a second test operation of capturing the fail data, and performing a third test operation of transmitting the fail data to the tester.