US Patent 7793187 Checking output from multiple execution units

Provided are a method and system checking output from multiple execution units. Execution units concurrently execute test instructions to generate test output, wherein test instructions are transferred to the execution units from a cache coupled to the execution units over a bus. The test output from the execution units is compared to determine whether the output from the execution units indicates the execution units are properly concurrently executing test instructions. The result of the comparing of the test output are forwarded to a design test unit.