ADLINK Technology NuDAQ cPCI-7249R, User Manual, Page: 37 / 74

Registers Format 23
72XX Series
User’s Manual
3 Registers Format
The detailed description of the registers format are specified in this
chapter. This information is useful for the programmers who wish
to handle the card by low-level programming. However, it is
strongly recommended that the user has a more in depth under-
standing of the PCI interface before starting any low-level pro-
gramming. In addition, the contents of this chapter can help the
user understand how to use the software driver to manipulate this
card.
3.1 PCI Plug and Play Registers
This PCI card functions as a 32-bit PCI target device to any mas-
ter on the PCI bus. There are three types of registers: PCI Config-
uration Registers (PCR), Local Configuration Registers (LCR) and
7224/7248/7296 registers.
The PCR, which is compliant to the PCI-bus specifications, is ini-
tialized and controlled by the Plug and Play PCI BIOS. Users can
study the PCI BIOS specification to understand the operation of
the PCR. Please contact PCISIG to acquire the specifications of
the PCI interface.
The PCI bus controller PCI-9052 is provided by PLX Technology,
Inc. (www.plxtech.com). For more detailed information on LCR,
please visit the PLX technology website to download the relative
information. Users are not required to understand the details of the
LCR if they are using the software library. The PCI Plug and Play
BIOS assigns the base address of the LCR. The assigned address
is located at offset 14h of PCR.
The 7224/7248/72968 registers are shown in the next section. The
base address, which is also assigned by the PCI Plug and Play
BIOS, is located at offset 18h of PCR. Therefore, users can read
the 18h of PCR to find the base address by using the BIOS func-
tion call.
Please do not try to modify the base address and interrupt which
are assigned by the PCI Plug and Play BIOS as it may cause
resource conflict in your system.