Example: PCI sound card burst
I still remember that when the PCI sound card was just launched, many users who installed both the PCI sound card and the PCI video card would encounter other large applications, such as the drop-down menu scroll bar, when processing the sound information, when the image changes, the sound card will generate intermittent "beep. In fact, the main reason is that the interrupt level of the PCI sound card is lower than the interrupt level of the PCI video card. When the video card is applied to the CPU, the data of the sound card will be paused, so the burst will occur. However, the problem will be solved when a dedicated bus-channel-based AGP video card is popular.
Do you know?
(1) How does the Chinese character system allow computers to display Chinese characters?
In addition to hardware interruptions, there are also software interruptions, which are caused by the execution of some commands. It is precisely the software interruptions that bring many functions to the operating system. The Int command is very famous. In the past, the computer can only display Spanish, while the Chinese character system can display the interrupt command through the int 10 h screen, so that the computer can also display Chinese.
(2) Interruptions also give viruses a chance
The virus uses software interrupt commands to tamper with the interrupt, so as to provide services for transmission and excitation. For example, the scheduled interrupt commands of int 08h and INT 1ch are called 18.2 times per second, some viruses use their recording to determine the excitation conditions. The Int H keyboard inputs the interrupt command. The virus is used to monitor the user's keys. The INT 13 H disk Input and Output interrupt commands, boot viruses are used for Infectious Disease Viruses and formatting disks.
| IRQ Allocation Table |
| Interrupted |
Purpose |
| Interrupt 0 |
System Timer |
| Interrupt 1 |
Keyboard |
| Interrupt 2 |
Programmable Interrupt Controller |
| Interrupt 3 |
Com2 |
| Interrupt 4 |
COM1 |
| Interrupt 5 |
Available for users (Sound Card) |
| Interrupt 6 |
Floppy Controller |
| Interrupt 7 |
Parallel Port 1 |
| Interrupt 8 |
System CMOS/clock |
| Interrupt 9 |
Cascade relationship with IRQ 2, which is retained by the System |
| Interrupt 10 |
Optional for users (generally used for sound cards, NICS, graphics cards, or SCSI adapters) |
| Interrupt 11 |
Optional for users (generally used for sound cards, NICS, graphics cards, or SCSI adapters) |
| Interrupt 12 |
PS/2 mouse |
| Interrupt 13 |
Mathematical coprocessor |
| Interrupted 14 |
First ide Controller |
| Interrupted 15 |
Second ide Controller |
3. How many interruptions can I use?
You may ask, how many IRQ is enough for a computer? The answer is: IRQ has never been enough! Let's see why this is said. The computer has 16 IRQ (0 ~ 15) Five IRQ (0, 1, 6, 8, 13) are retained by the system and cannot be used. Two IRQ can only be used as one (2 and 9 ), some computers require more than three IRQ devices, such as one hard disk, one video card, and one mouse. In this way, you need to add at least three printers, then there will be fewer. There are no more than 10 in the rough calculation, and there are only 6 in the end.
2. Now let's take a look at the computer interruption.
1. Windows 9x/me
Right-click "my computer" on the desktop, select "properties", go to the "Device Manager" tab, right-click "computer" in the list, and select "properties ", in the displayed window, select "interrupt request (IRQ)". The following lists the devices associated with the current interruption of the system. 2. Windows 2000/XP
Right-click my computer on the desktop, select Properties, go to the hardware tab, and click Device Manager, in the "Device Manager" window, click "view → sort resources by type", and then double-click "interrupt request (IRQ, in this way, the system will display the device corresponding to the current interrupt (01 the explanation of the PCI interrupt will be quite complicated, so we will not repeat it here. If you are interested, you can refer to relevant reference books for details .).
Tips
Why do PCI devices use IRQ 11?
When viewing IRQ resources, you may find that many PCI devices are using IRQ 11. This is because, technically, the system has two groups of hardware interruptions: ISA interruption and PCI interruption. Generally, 16 interruptions refer to ISA interruption, there are four PCI interruptions (INTA #, intb #, intc #, and intd #. Generally, all PCI cards use INTA #). To enable the PCI Card to work on the PCI bus, PCI interrupt must be mapped to an unused ISA interrupt and there are very few ISA interrupt resources. Therefore, both bios and Windows use the "pci irq Guide" function, it allows Windows to allocate an IRQ to multiple PCI devices, and dynamically controls the use of this disconnect for PCI devices. Instance: optimized IRQ to improve motherboard performance (applicable to Windows 2000/XP)
The main optimization object here is "system CMOS/clock" (system CMOS/real time clock), where the disconnection is generally IRQ 8. Open the Registry Editor, find [HKEY_LOCAL_MACHINE \ SYSTEM \ CurrentControlSet \ Control \ prioritycontrol], create a dual-byte value named irq8priority in the right pane, and set its value to 1. This technique can improve the performance of the entire motherboard.
