 Hello and welcome to this presentation of the STM32H7 Asynchronous Interrupts and Events Controller, or EXTI. The EXTI controller provides up to 89 independent events, split into two categories, configurable events, and direct events. The EXTI controller can be configured to wake up CPU1, CPU2, or both independently. It can also be used to wake up only the D3 domain for autonomous operation. Applications benefit through smarter usage of low power modes, taking advantage of the capability to wake up the external communication or requests. The EXTI controller provides interrupt and event generation functions, as well as the capability to wake up the processors and the D3 domain from stop modes. Configurable events allow the user to select which active edge generates an interrupt or event with a dedicated status flag for each line. Requests on configurable lines can also be generated by software. Configurable events are linked with external interrupts from general purpose input outputs, comparators, programmable voltage detector, real time clock, low power timer, window watchdog, Ethernet controller, and HDMI CEC. Direct events provide an interrupt or event from peripherals having a status flag requiring to be cleared. For direct events that are part of the D3 domain and which have a pending mask and status register, an interrupt may be generated. EXTI wake up events may be configured to wake up a CPU or the D3 domain. Configurable events need to be cleared by the corresponding CPU which has been awakened. The D3 domain wake up events must be cleared by the D3 domain. Some peripherals are able to wake up the D3 domain autonomous mode where both CPUs remain in C stop mode. In this mode the D3 domain is able to transfer data between communication peripherals and memory using the BDMA and DMA MUX2. The BDMA trigger is used to clear the D3 autonomous mode wake up event and re-enter low power mode. The timers can be used to wake up the D3 domain autonomous mode on a regular basis, for example to perform polling tasks. In addition, timers can be used to clear the D3 autonomous mode wake up event and re-enter low power mode. As shown in this figure, the EXTI consists of a register block accessed via an APB interface, an event input trigger block, and a masking block. The register block contains all EXTI registers. The event input trigger block provides event input edge triggering logic. The masking block provides the event input distribution to the different wake up, interrupt and event outputs and their masking.