User manual

27 Chapter 2
Shared IRQ Mode
In this mode, all channels in card share the same interrupt (IRQ), and
interrupt status register is available for determining the interrupt source.
Select an IRQ, which is not already in use by another card in the system.
If you are installing more than one card, set them to different IRQ num-
ber. Jumper Bank JP1 controls the card IRQ. Simply place the jumper on
the interrupt level as shown in the following figure. You can set share
IRQ selection as the following table shows.
Figure 2.25: IRQ Selection
2.3.6 Interrupt Status Register Setup (SW2 or S5)
When data arrives at one of the eight ports, it will generate an interrupt in
the interrupt register. The software can read this, and identify immedi-
ately which port generated the interrupt. This saves time, and makes pro-
gramming easier. In Windows 98/2000/XP environment, when a data bit
of the interrupt status register is set to 1, the corresponding channel is
select to generate an interrupt. If the bit is 0, then no interrupt status regis-
ter, as shown in the following figure and table.
Item Jumper
PCL-746+ JP4
PCL-846A/B JP11
PCL-849A/B/+ JP1