These application use cases show possible MCU to MCU communication.

Figure 2-6 example shows MCU to MCU communication with SPI. When both sides idle the communication by raising both INC and IND HIGH for longer than the STANDBY state enable delay time, t_{LP_EN}, the isolator transitions to STANDBY state and turns off the high-speed data channels. MCU1 can re-initiate communication by pulling INC (nCS) LOW, waking-up the isolator, turning on the high-speed channels and pulling OUTC LOW. MCU2 wakes-up because of OUTC falling LOW and generates an interrupt or equivalent to wake-up MCU2 to prepare for the high-speed communication.

Similarly, when MCU2 has data ready to communicate, MCU2 pulls IND (nDR) LOW, waking-up the isolator, turning on the high-speed channels and pulling OUTD LOW. MCU1 wakes-up because of OUTD falling LOW and generates an interrupt or equivalent to wake-up MCU1 to prepare for the high-speed communication.

Figure 2-7 example shows MCU to MCU communication with a dedicated data bus in each direction. When both sides idle the communication the isolator transitions to STANDBY state and turns off the high-speed data channels. When MCU1 communicates by pulling INC LOW for a data enable signal and the isolator wakes-up and turns on the high-speed channels. MCU2 uses an interrupt IO or equivalent on OUTC to wake-up and prepare for high-speed communication. Similarly, when MCU2 has data ready to communicate, MCU2 pulls IND LOW for data enable and the isolator wakes-up and turns on the high-speed channels. MCU1 uses an interrupt IO or equivalent on OUTD to wake-up and prepare for high-speed communication.