An apparatus may include a memory array, a test circuit coupled to the memory array, a counter circuit coupled to the test circuit and an input/output (I/O) circuit coupled to the counter circuit. During a test operation, the test circuit may receive blocks of data from the memory array and compare the data to detect errors in the blocks of data. The counter circuit may increment a count value in response to detection of an error by the test circuit, and the I/O circuit may provide the count value to an output. The test circuit may also provide test comparison data based on the received blocks of data, and the I/O circuit may provide one of the count value and the test comparison data to the output.