CyberResearch PCIDIO 48H - Manual (Page 29)

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• Registers Format
3
Registers Format
Detailed descriptions of the register's format are specified in this
chapter. This information is quite useful for the programmers who wish to
handle the card through low-level programming. However, we suggest
users understand more about the PCI interface before beginning any low-level
programming. In addition, the contents of this chapter can help users
understand how to use a software driver to manipulate this card.
3.1 PCI PnP Registers
This PCI card functions as a 32-bit PCI target device to any master on the
PCI bus. There are three types of registers: PCI Configuration Registers
(PCR), Local Configuration Registers (LCR) and PCIDAC 082 registers.
The PCR, which is compliant with PCI-bus specifications, is initialized
and controlled by the plug & play (PnP) PCI BIOS. User's can study the PCI
BIOS specification to understand the operation of the PCR.
The PCI bus controller PCI-9050 is provided by PLX technology Inc.
(www.plxtech.com). For more detailed information of LCR, please visit PLX
technology’s web site to download relative information. It is not necessary
for users to understand the details of the LCR if you use the software library.
The PCI PnP BIOS assigns the base address of the LCR. The assigned
address is located at offset 14h of PCR.
The PCIDAC 0812 registers are shown in the next section. The base address,
which is also assigned by the PCI PnP BIOS, is located at offset 18h of
PCR. Therefore, users can read the 18h of PCR to know the base address
by using the BIOS function call.
Please do not try to modify the base address and interrupt which assigned
by the PCI PnP BIOS, it may cause a resource conflict in your system.