User`s guide

Registers Format • 13
3
Registers Format
The detailed descriptions of the registers format are specified in this
chapter. This information is quite useful for the programmers who wish to
handle the card by low-level programming. However, we suggest users
have to understand more about the PCI interface then start any low-level
programming. In addition, the contents of this chapter can help users
understand how to use 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 PCI-6308 registers.
The PCR, which is compliant to the 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. Please
contact with PCISIG to acquire the specifications of the PCI interface.
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 PCI-6308 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.