Interrupts on STM32 MCUs come in two flavors: internal and external. Both types of interrupts use the same core peripheral in the Cortex-M core: the Nested Vectored Interrupt Controller, or NVIC.

“This new MCU family brings the benefits of the STM32 architecture to extra applications in the industrial, medical, building automation, home audio, and domestic appliance markets,” said Jim Nicholas ...

For instance, here he’s using an STM32 Discovery board to drive an AMD Radeon HD 2400 graphics card. The ARM microcontroller isn’t actually using the PCIe interface on the card.