Embodiments combine error correction code (ECC) and transparent memory built-in self-test (TMBIST) for memory fault detection and correction. An ECC encoder receives input data and provides ECC data for data words stored in memory. Input XOR circuits receive the input data and output XOR'ed data as payload data for the data words. Output XOR circuits receive the payload data and output XOR'ed data. An ECC decoder receives the ECC data and the XOR'ed output data and generates error messages. Either test data from a controller running a TMBIST process or application data from a processor executing an application is selected as the input data. Either test address/control signals from the controller or application address/control signals from the processor are selected for memory access. During active operation of the application, memory access is provided to the processor and the controller, and the memory is tested during the active operation.