Patent US 7,627,797

A method, apparatus, and system are provided for testing multi-core processors. The testing includes a test control mechanism and a multi-core processor including a set of cores with at least one core having a test access port controller (TAPC), distributed data, and a set of distributed control registers. The multi-core processor and the test control mechanism further having a configuration to provide testing the multi-core processor. The test control mechanism is modified to simultaneously test multiple cores.