Abstract: A system for internally monitoring an integrated circuit, wherein the contents of memory locations in the integrated circuit can be displayed on a dedicated display unit via a graphical interface device provided in the integrated circuit. The system provides a built-in means for observing the internal state of both firmware and hardware (as applicable) on the integrated circuit device. This facilitates the development of, and ongoing health monitoring of, the device in any system into which it may be incorporated. The provision of a graphical interface device provides a relatively high bandwidth for the outgoing data and so allows the internal state of the device to be monitored in real time.