The PSoC MCU has a great deal of interconnect flexibility but it is not unlimited. A typical digital PSoC block can have input from 16 sources, which includes four Input and four output digital Interconnects, which can inturn be routed to the corresponding Global In/Out interconnects. Thus, the input of a digital block can be given from any GPIO pin. The output of a typical digital block can connect to four output interconnects, which can in turn be routed to the corresponding Global out interconnects. Thus, the outut of a digital block can also be routed to any GPIO pin. This creates the flexibility to determine the port a signal comes out on, as well as the side of the package. However, at a given time, an input and output of a digital pin can be given from or routed to only 4 pins.