Hence, the required control signals are uniquely determined by the following information:

• Contents of the control counter.
                               
• Contents of the instruction register.
                                    
• Contents of the condition code and other status flags.

The external inputs represent the state of the CPU and various control lines connected to it, such as MFC status signal. The condition codes/ status flags indicates the state of the CPU. These includes the status flags like carry, overflow, zero, etc.