Interrupt Assignments; Table 1-3. Interrupt Assignments - Dell 2200 Service Manual

Interrupt Assignments

Table 1-3. Interrupt Assignments

IRQ Line Used By/Available
IRQ0 Generated by system timer
IRQ1 Generated by keyboard controller to indicate that keyboard's out-
put buffer is full
IRQ2 Generated internally by interrupt controller to enable IRQ8
through IRQ15
IRQ3 Generated by super I/O controller to indicate that device con-
and nected to corresponding serial port requires service (IRQ3 for
IRQ4 COM2 or COM4; IRQ4 for COM1 or COM3)
IRQ5 Available for use by expansion card unless this IRQ line is used
by secondary parallel port
IRQ6 Generated by super I/O controller to indicate that diskette or tape
drive requires service
IRQ7 Generated by super I/O controller to indicate that device con-
nected to parallel port requires service
IRQ8 Generated by keyboard controller for each tick of RTC
IRQ9 Available for use by expansion card
IRQ10 Available for use by expansion card
IRQ11 Available for use by expansion card
IRQ12 Generated by keyboard controller to indicate that mouse's output
buffer is full
IRQ13 Generated by math coprocessor to indicate coprocessor error
IRQ14 Available for use by expansion card unless the IRQ line is in use
by the SCSI controller
IRQ15 Available for use
System Overview 1-17