Chapter 2 Hardware Description
AI5TV Motherboard User’s Manual
9
2.7 Interrupt Request Lines (IRQ)
There are a total of 15 IRQ lines available on the motherboard.
Peripheral devices use interrupt request to notify CPU for the service
required. The following table shows the IRQ used by the devices on the
motherboard:
Level
Function
IRQ0
System Timer Output
IRQ1
Keyboard
IRQ2
Interrupt Cascade
IRQ3
Serial Port #2
IRQ4
Serial Port #1
IRQ5
Parallel Port #2
IRQ6
Floppy Disk Controller
IRQ7
Parallel Port #1
IRQ8
Real Time Clock
IRQ9
Software Redirected to Int 0Ah
IRQ10
Reserved
IRQ11
Reserved
IRQ12
Reserved
IRQ13
80287
IRQ14
Primary IDE
IRQ15
Secondary IDE
2.8 Onboard PCI-EIDE
The PCI-EIDE controller is part of the 430VX PCIset. It supports PIO
mode 3/4 and bus mastering . The peak transfer rate of PIO mode 3/4
can be as high as 17MB/sec. Using HDDs that support bus mastering,
the peak transfer rate can reach 22MB/sec.
There are two IDE connectors, primary IDE and secondary IDE. With
two devices per connector, up to four IDE drives are supported.
2.9 Onboard Multi-I/O
The onboard multi-I/O chip, Winbond W83877, provides two serial
port, one parallel port and one floppy controller. The serial ports are
16550 UART compatible. The parallel port supports high speed
EPP/ECP mode.
The floppy controller supports up to 2.88 MB format. The I/O port
addresses of the serial and parallel ports are programmable via BIOS
set-up. Each I/O can be individually disabled.
