What are External Hardware Interrupts?

External Hardware Interrupts Explained

External hardware interrupts provide a way for devices to interrupt the processor and alert it to the arrival of new data. This type of interrupt is most commonly used for communication between two devices, such as a mouse or keyboard. External hardware interrupts provide a way for devices to interrupt the processor and alert it to the arrival of new data.

How It Works

In order for external hardware interrupts to work, there must first be a way for the device to alert the processor that it has some data or information for it. This is done through a signal sent from the device to the processor; this is called an interrupt request. Once the processor receives this interrupt request, it will suspend any current operations being performed and then begin executing a special type of code known as an interrupt service routine (ISR). The ISR is responsible for reading the data from the device and then deciding what to do next.

Types of External Devices

The type of device that is sending the interrupt request will determine which kind of ISR code needs to be executed. Common examples of devices that trigger external hardware interrupts are mice, keyboards, and other devices, such as serial and network cards. When the processor receives an interrupt request, it must first determine which type of device is responsible for the request before it can execute the appropriate ISR.

Benefits of External Hardware Interrupts

One of the main benefits of using external hardware interrupts is that they provide a fast and reliable way for devices to communicate with the processor. Without interrupts, the processor would have to constantly poll the devices to see if there was any data or information needing to be processed, resulting in wasted clock cycles. By using external hardware interrupts, the processor is alerted immediately when there is new data needing processing, ensuring faster response times.

Conclusion

External hardware interrupts provide a way for devices to communicate quickly and reliably with the processor. By sending an interrupt request, the processor is alerted and able to start executing the appropriate ISR code. This helps reduce the amount of time that the processor spends polling devices, resulting in more efficient operation.