> Can anyone explain their relationship and difference among them? It > is very appreciated if you can make some comments. thanks.
I think IRQ number, interrupt number are quite similar things. You can check PIC [1] first, especially 8259A [2]. When a device raise an interrupt, the interrupt is delivered to CPU through PIC. Each device attaches itself to one of PIC's pins. Thus, when we say the IRQ number of device X is Y, it means device X attaches itself to PIC's pin Y. PIC will deliver the highest priority interrupt to the CPU. The term "interrupt line" might appear in PCI context [3]. BIOS usually uses interrupt line to represent what PIC pin the device attatches to. Note that PIC (Programmable Interrupt Controller) and PCI (Peripheral Component Interconnect) are different things. GPIO mostly is used on SoC. It depends on the vendor how to use GPIO. One of GPIO capabilities is similar to PIC, I guess. But I leave this to SoC experts. I strongly recommend the book [5] if you want to learn how things work. HTH, chenwj [1] http://en.wikipedia.org/wiki/Programmable_Interrupt_Controller [2] http://en.wikipedia.org/wiki/Intel_8259 [3] http://en.wikipedia.org/wiki/Conventional_PCI [4] http://en.wikipedia.org/wiki/General_Purpose_Input/Output [5] 系统虚拟化:原理与实现 -- Wei-Ren Chen (陳韋任) Computer Systems Lab, Institute of Information Science, Academia Sinica, Taiwan (R.O.C.) Tel:886-2-2788-3799 #1667 Homepage: http://people.cs.nctu.edu.tw/~chenwj