What is the maximum number of dedicated IRQs most USB devices typically need?

USB devices are designed to minimize the demand for individual hardware resources such as IRQs (Interrupt Requests). Typically, most USB devices require only one dedicated IRQ to function properly. This efficient design is due to the way USB handles data. USB uses a polling mechanism, meaning the USB host controller communicates with multiple devices sequentially, rather than each requiring its own unique IRQ.

This approach allows several USB devices to share the same IRQ, reducing the complexity of the system and allowing for more devices to be connected without exhausting available IRQ resources. The use of a single IRQ for USB devices is a significant aspect of USB architecture, enabling easy expansion of devices and enhancing compatibility across systems.