The Emulating a Digital MUX software example demonstrates how to use GPIO interrupts to emulate a digital MUX. Similar to a logic based MUX, the MCU uses select signals (S0 and S1) to determine which input channel (C0, C1, C2, and C3) is output at a given time. Doing this through the MCU not only eliminates the need for an external MUX, but also allows flexible pin assignments that can help aid PCB routing. This specific example emulates a 4-input channel, 2-select-signal digital MUX.

Figure 1-1 displays the functional block diagram for this subsystem.

Figure 1-1 Subsystem Functional Block Diagram