"Convert" IRQ

From: http://blog.pfan.cn/hujing/30734.html

 

IRQ is short for interrupt request. Each component in the computer has an independent IRQ. In addition to the PCI bus PCI Card, each component occupies an IRQ and cannot be reused.

Because the CPU continues to be busy during computer operation, when the hardware interface device starts or ends sending and receiving information, the CPU needs to process information computing, IRQ sends an interrupt request signal to the CPU, allowing the CPU to store ongoing work, and then suspends the work at hand to handle the requirements of peripheral hardware. This is the role of the interrupt request.

There are two chips in each system to provide 16 IRQ, most of which have a fixed arrangement. For example, IRQ 0 is fixed as a system timer, and IRQ 1 is a keyboard. Because each IRQ can only be used by one device, the number of IRQ is very limited. If many accessories are installed on the computer, IRQ will not be used properly, therefore, two devices may share the same IRQ, and an IRQ conflict may occur, resulting in unavailability of the device.

The simplest solution is to manually adjust the IRQ allocation in the Hardware Device Manager of the operating system, or make adjustments in the BIOS. If IRQ is not suitable for use, you can use other methods to solve this problem. For example, the PCI bus can share an IRQ, so you can basically increase the PCI plug-in card, it will not be restricted by IRQ. The second is to use USB transmission to solve the problem. Because the USB control chip only occupies One IRQ, not all USB products need to exclusively occupy One IRQ. Therefore, in theory, up to 127 peripheral products can be connected, at present, products with USB transmission interfaces are becoming more and more popular. Therefore, peripheral devices with low transmission speed requirements will gradually develop towards USB interfaces in the future.