A tester comprises test logic and a connector for at least one
device under test. The connector, which may comprise a
wafer probe for dice on a
wafer or a
test fixture or either packaged
integrated circuit devices or circuit board modules, has connections for the
device under test that present an impedance selected to emulate the
characteristic impedance of an end-use environment of the
device under test. For example, in an embodiment in which the device under test comprises DDR memory and the end-use environment is a DDR
memory module, the
characteristic impedance is approximately 60 ohms. Thus, the tester of the present invention can accurately simulate
operational behavior in an end-use environment of the device under test. Because this accurate
simulation is available even for dice on a
wafer, the needless expense associated with packaging defective dies and assembling defective dies into modules can be avoided. The test logic, which is couplet to the connector for communication with the device under test, transfers test commands and
test data to (tic device under test. The
test data and commands are utilized to perform multiple types of tests, including tests of the memory core and
internal logic of the device under test. In this manner, the need for multiple types of testers is reduced or eliminated.