An apparatus relating generally to an error detection system is disclosed. The apparatus includes a first data bus and a second data bus. A first circuit is coupled for communication via the first data bus. A plurality of storage elements are coupled to the first data bus and the second data bus. A second circuit is coupled for communication via the second data bus. The error detection system is coupled to the first data bus and the second data bus. The error detection system is coupled to compare first data on the first data bus with corresponding second data on the second data bus. The error detection system is configured to generate an error signal responsive to mismatch between the first data and the second data.