Chapter 4: Address Selection - IBM LPCI-COM-8SM User Manual

Chapter 4: Address Selection

The card uses one address space. COM A, COM B, COM C, COM D, COM E, COM F, COM G
and COM H each occupy eight consecutive register locations. The interrupt register which
indicates which port or ports caused the interrupt is located at base address + 64.
PCI architecture is Plug-and-Play. This means that the BIOS or Operating System determines
the resources assigned to PCI cards rather than you selecting those resources with switches or
jumpers. As a result, you cannot set or change the card's base address. You can only
determine what the system has assigned.
To determine the base address that has been assigned, run the PCIFind.EXE utility program
provided. This utility will display a list of all of the cards detected on the PCI bus, the addresses
assigned to each function on each of the cards, and the respective IRQs (if any) allotted.
Alternatively, some operating systems (Windows 95/98/2000/XP) can be queried to determine
which resources were assigned. In these operating systems, you can use the Device Manager
utility from the System Applet of the control panel. The card is installed in the Data Acquisition
class of the Device Manager list. Selecting the card, clicking Properties, and then selecting the
Resources Tab will display a list of the resources allocated to the card.
The PCI bus supports 64K of I/O space. Your card's addresses may be located anywhere in the
0000 to FFFF hex range.
PCIFind uses the Vendor ID and Device ID to search for your card, then reads the base address
and IRQ.
If you want to determine the base address and IRQ yourself, use the following information.
The Vendor ID for the card is 494F. (ASCII for "IO")
The Device ID for the card is 10E8h.
15 Manual LPCI-COM-8SM