An IC that includes an eye viewer and a BER checker coupled to the eye viewer, where the BER checker receives a serial data signal from the eye viewer, is provided. In one implementation, the BER checker receives the serial data signal from the eye viewer without the serial data signal passing through a deserializer. In one implementation, the BER checker compares the serial data signal against a reference data signal to determine the BER for the serial data signal. In one implementation, the IC includes an IC core coupled to the eye viewer and the BER checker, where the BER checker is outside the IC core. In one implementation, the BER checker is a dedicated BER checker. In one implementation, the BER checker includes an exclusive OR gate, a programmable delay circuit coupled to the exclusive OR gate, and an error counter coupled to the exclusive OR gate.