mirror of https://github.com/Qortal/Brooklyn
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
24 lines
994 B
24 lines
994 B
=============== |
|
What is an IRQ? |
|
=============== |
|
|
|
An IRQ is an interrupt request from a device. |
|
Currently they can come in over a pin, or over a packet. |
|
Several devices may be connected to the same pin thus |
|
sharing an IRQ. |
|
|
|
An IRQ number is a kernel identifier used to talk about a hardware |
|
interrupt source. Typically this is an index into the global irq_desc |
|
array, but except for what linux/interrupt.h implements the details |
|
are architecture specific. |
|
|
|
An IRQ number is an enumeration of the possible interrupt sources on a |
|
machine. Typically what is enumerated is the number of input pins on |
|
all of the interrupt controller in the system. In the case of ISA |
|
what is enumerated are the 16 input pins on the two i8259 interrupt |
|
controllers. |
|
|
|
Architectures can assign additional meaning to the IRQ numbers, and |
|
are encouraged to in the case where there is any manual configuration |
|
of the hardware involved. The ISA IRQs are a classic example of |
|
assigning this kind of additional meaning.
|
|
|