Ampro Corporation 486E manual Interrupt Assignments, IRQ11 IRQ7

Little Board™/486e Technical Manual

Interrupt Assignments

Interrupt 4 (IRQ4) is assigned to Serial 1 and Interrupt 3 (IRQ3) to Serial 2. These assignments can be disabled, but they cannot be changed. Serial 3 and Serial 4 can share their interrupts, using a “wired-or” configuration, they can use independent IRQs, or they can be disabled and use no interrupt at all. Jumper options are provided to independently select the wired-or configuration or independent interrupts for Serial 3 and Serial 4. See Figure 2–3 through 2–5.

W7

Shared

Non-Shared

Figure 2–3. Shared Wired-Or Configuration

W8

IRQ11

IRQ7

Figure 2–4. Serial 3 Interrupt Configuration (W8)

W9

IRQ10

IRQ5

Figure 2–5. Serial 4 Interrupt Configuration (W9)

When a serial port is disabled, its IRQ is available to other peripherals installed on the PC/104 expansion bus.

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