Avoiding interrupt assignment conflicts – Dell Latitude C600 User Manual

Page 131

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Replace the

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Avoiding Interrupt Assignment Conflicts

Problems can arise if two devices attempt to use the same interrupt request (IRQ) line. To avoid this type of
conflict, check the documentation for the default IRQ line setting for each installed device. Then consult

Table 2

to configure the device for one of the available IRQ lines.

NOTES: Installed devices cannot share the same COM port address. The default address of your
computer's serial port is COM1.

For information about IRQ assignments, refer to your Windows operating system documentation.

Table 2. IRQ Line Assignments

IRQ

Line

Reserved/Available

IRQ0

Reserved; used by the system timer

IRQ1

Reserved; used by the keyboard controller to signal that the keyboard output buffer is full

IRQ2

Reserved; used internally by the interrupt controller to enable IRQ8 through IRQ15

IRQ3

For a PC Card unless the integrated serial port or infrared port is configured for COM2 or COM4

IRQ4

For a PC Card unless the integrated serial port or infrared port is configured for COM1 (the
default) or COM3

IRQ5

For the audio controller

IRQ6

Reserved; used by the diskette drive controller

IRQ7

For a PC Card or audio controller if the parallel port is disabled

IRQ8

Reserved; used by the system I/O controller's real-time clock

IRQ9

Reserved; used by the video controller

IRQ10 For a PC Card or audio controller unless a docking station or port replicator is attached

IRQ11 For a PC Card; used by USB, PC Card, and audio controllers

IRQ12 Reserved; used by the keyboard controller to indicate that the output buffer of the DualPoint

integrated pointing device or the external PS/2 mouse is full

IRQ13 Reserved; used by the math coprocessor

IRQ14 Reserved; used by the hard-disk drive to indicate that the drive requires the attention of the

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