System IRQ's

Discussion in 'Computer Information' started by Jerry G., Jul 31, 2004.

  1. Jerry G.

    Jerry G. Guest

    This is machine that shows 24 IRQ channels. This machine belongs to one of
    my clients.

    ___________________________________________________

    Machine Summary:

    OS Name Microsoft Windows XP Professional
    Version 5.1.2600 Service Pack 1 Build 2600
    OS Manufacturer Microsoft Corporation
    System Name DELTA_MAIN_3
    System Manufacturer To Be Filled By O.E.M.
    System Model To Be Filled By O.E.M.
    System Type X86-based PC
    Processor x86 Family 15 Model 2 Stepping 9 GenuineIntel ~2598 Mhz
    Processor x86 Family 15 Model 2 Stepping 9 GenuineIntel ~2598 Mhz
    BIOS Version/Date American Megatrends Inc. 1009.008, 03-07-21
    SMBIOS Version 2.3
    Windows Directory C:\WINDOWS
    System Directory C:\WINDOWS\System32
    Boot Device \Device\HarddiskVolume1
    Locale Canada
    Hardware Abstraction Layer Version = "5.1.2600.1106 (xpsp1.020828-1920)"
    User Name DELTA_MAIN_3\gerry
    Time Zone Eastern Daylight Time
    Total Physical Memory 1,024.00 MB
    Available Physical Memory 599.80 MB
    Total Virtual Memory 3.40 GB
    Available Virtual Memory 2.73 GB
    Page File Space 2.40 GB
    Page File C:\pagefile.sys

    __________________________________________________

    This is the IRQ list on the machine that I am working on, extracted from
    System Information. IRQ 18 concerns me, with the sharing of one of the USB
    controllers and the Ultra ATA hard drive controler. Note that the display
    card is on IRQ 16, and is shared with 2 of USB Host Controllers.

    I am curious to know where 2, 3, 7, and 11 are in this system, and their
    use.


    IRQ 0 System timer OK
    IRQ 1 Standard 101/102-Key or Microsoft Natural PS/2 Keyboard OK
    IRQ 4 Communications Port (COM1) OK
    IRQ 6 Standard floppy disk controller OK
    IRQ 8 System CMOS/real time clock OK
    IRQ 9 Microsoft ACPI-Compliant System OK
    IRQ 10 Intel(R) 82801EB SMBus Controller - 24D3 OK
    IRQ 13 Numeric data processor OK
    IRQ 14 Primary IDE Channel OK
    IRQ 15 Secondary IDE Channel OK
    IRQ 16 ALL-IN-WONDER 9000 OK
    IRQ 16 Intel(R) 82801EB USB Universal Host Controller - 24D2 OK
    IRQ 16 Intel(R) 82801EB USB Universal Host Controller - 24DE OK
    IRQ 18 Intel(R) 82801EB USB Universal Host Controller - 24D7 OK
    IRQ 18 Intel(R) 82801EB Ultra ATA Storage Controllers OK
    IRQ 19 Intel(R) 82801EB USB Universal Host Controller - 24D4 OK
    IRQ 20 VIA OHCI Compliant IEEE 1394 Host Controller OK
    IRQ 21 Creative SB Audigy OK
    IRQ 21 Lava DSerial PCI PortA (COM4) OK
    IRQ 21 Lava DSerial PCI PortB (COM5) OK
    IRQ 22 3Com Gigabit LOM (3C940) OK
    IRQ 22 OHCI Compliant IEEE 1394 Host Controller OK
    IRQ 22 Standard Enhanced PCI to USB Host Controller OK
    IRQ 23 Standard Enhanced PCI to USB Host Controller OK
    IRQ 23 ALi PCI to USB Open Host Controller OK
    IRQ 23 U.S. Robotics V92 Fax PCI OK

    ________________________________________


    Sharing:

    I/O Port 0x00000000-0x00000CF7 PCI bus
    I/O Port 0x00000000-0x00000CF7 Direct memory access controller

    I/O Port 0x000003C0-0x000003DF Intel(R) 82865G\PE\P Processor to AGP
    Controller - 2571
    I/O Port 0x000003C0-0x000003DF ALL-IN-WONDER 9000

    IRQ 21 Creative SB Audigy
    IRQ 21 Lava DSerial PCI PortA (COM4)
    IRQ 21 Lava DSerial PCI PortB (COM5)

    IRQ 22 3Com Gigabit LOM (3C940)
    IRQ 22 OHCI Compliant IEEE 1394 Host Controller
    IRQ 22 Standard Enhanced PCI to USB Host Controller

    IRQ 23 Standard Enhanced PCI to USB Host Controller
    IRQ 23 ALi PCI to USB Open Host Controller
    IRQ 23 U.S. Robotics V92 Fax PCI

    IRQ 16 ALL-IN-WONDER 9000
    IRQ 16 Intel(R) 82801EB USB Universal Host Controller - 24D2
    IRQ 16 Intel(R) 82801EB USB Universal Host Controller - 24DE

    IRQ 18 Intel(R) 82801EB USB Universal Host Controller - 24D7
    IRQ 18 Intel(R) 82801EB Ultra ATA Storage Controllers

    Memory Address 0xA0000-0xBFFFF PCI bus
    Memory Address 0xA0000-0xBFFFF Intel(R) 82865G\PE\P Processor to AGP
    Controller - 2571
    Memory Address 0xA0000-0xBFFFF ALL-IN-WONDER 9000

    I/O Port 0x000003B0-0x000003BB Intel(R) 82865G\PE\P Processor to AGP
    Controller - 2571
    I/O Port 0x000003B0-0x000003BB ALL-IN-WONDER 9000

    I/O Port 0x0000C000-0x0000CFFF Intel(R) 82865G\PE\P Processor to AGP
    Controller - 2571
    I/O Port 0x0000C000-0x0000CFFF ALL-IN-WONDER 9000

    ______________________________________


    --

    Jerry G.
    ==========================


    This pertains more to win98 but may provide some help.

    There are 16 IRQs (15 usable) in a computer system. Here is a typical
    assignment of these IRQs:

    IRQ 0 System- System Timer
    IRQ 1 System- Keyboard
    IRQ 2 System- Cascadeable PIC (programmable interrupt controller), controls
    IRQ 8-15
    IRQ 3 System- Serial Port (COM 2 and COM4)
    IRQ 4 System - Serial Port (COM 1 and COM3)
    IRQ 5 Available- General Adapter Use
    IRQ 6 System- Diskette Controller
    IRQ 7 System- Printer 1
    IRQ 8 System- CMOS Real-time clock
    IRQ 9 Available- General Adapter Use
    IRQ 10 Available- General Adapter Use
    IRQ 11 Available- General Adapter Use
    IRQ 12 System- Mouse Port
    IRQ 13 System- Math Co-processor (even though this is built into the CPU, it
    still uses an IRQ)
    IRQ 14 System- Hard Disk Controller
    IRQ 15 Available- General Adapter Use



    As you can see, there are five (5) IRQs that are not assigned by the system
    design. Of these, one usually goes to the graphics card, one to the USB
    ports, and one to the modem. That leaves two (2) available IRQs for
    everything else. With care (and use of the proper cards), this is normally
    sufficient.



    Loading Sequence for Additional cards:

    First:
    Internal Modem (PCI)
    Second:
    Sound Card (PCI or ISA)
    Third:
    Network Card, a.k.a. NIC (PCI or ISA)
    Fourth:
    DVD Devices requiring Dxr3 Decoder Board (PCI)
    Note: Some video decoder boards require two (2) IRQs for complete
    functionality. Check with your video decoder card manufacturer for video
    decoder support and requirements.
    Fifth:
    SCSI Adapter (PCI) (This assumes that the system does not have a SCSI hard
    drive.)
    Sixth:
    Any others.
     
    Jerry G., Aug 6, 2004
    #21
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  2. Jerry G.

    Thor Guest


    The additional IRQs are "virtual" IRQs, not true hardware IRQ lines. There
    are still only 16 actual hardware IRQ lines (0-15).
     
    Thor, Aug 6, 2004
    #22
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  3. In Windows, peripheral component interconnect (PCI) devices can share
    IRQs. In accordance with the Plug and Play capability that is defined
    by the PCI specification, adapters are configured by the computer BIOS
    and are then examined by the operating system and changed if
    necessary. Typically, PCI devices have IRQs shared among them,
    especially on Advanced Configuration and Power Interface (ACPI)
    computers that have Windows ACPI support enabled.

    In Windows XP, Device Manager may list some or all the devices on your
    ACPI motherboard as using the same IRQ (IRQ 9). (To view the list of
    resources, click either Resources by type or Resources by connection
    on the View menu). No option is available to change the IRQ setting.
    Windows takes advantage of the ACPI features of the motherboard,
    including advanced PCI sharing. The PCI bus uses IRQ 9 for IRQ
    steering. With this feature, you can add more devices without IRQ
    conflicts.

    Further reading http://support.microsoft.com/default.aspx?scid=kb;EN-US;314068

    You can check which device is connected to which USB port in Device
    Manager by right clicking on each instance of USB Root Hub, selecting
    Properties, then the Power tab. Any devices assigned will show up
    there.
     
    [email protected], Aug 10, 2004
    #23
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