
PCI Functional Description
Configuration Registers
3-6
SYM53C810A Data Manual
Configuration Registers
T he Configuration registers are accessible only by
system BIOS during PCI configuration cycles, and
are not available to the user at any time. No other
cycles, including SCRIPT S operations, can access
these registers.
T he lower 128 bytes hold configuration data while
the upper 128 bytes hold the SYM53C810A oper-
ating registers, which are described in Chapter
Five, “Operating Registers.” T he operating regis-
ters can be accessed by SCRIPT S or the host pro-
cessor.
Note: the configuration register descriptions are
provided for general information only, to
indicate which PCI configuration addresses
are supported in the SYM53C810A.
For detailed information, refer to the PCI Specifi-
cation.
Figure 3-1 shows the PCI configuration registers
implemented by the SYM53C810A. Addresses
40h through 7Fh are not defined.
All PCI-compliant devices, such as the
SYM53C810A, must support the Vendor ID,
Device ID, Command, and Status Registers. Sup-
port of other PCI-compliant registers is optional.
In the SYM53C810A, registers that are not sup-
ported are not writable and return all zeroes when
read. Only those registers and bits that are cur-
rently supported by the SYM53C810A are
described in this chapter. For more detailed infor-
mation on PCI registers, please see the PCI Speci-
fication.
*I/O Base is supported
**Memory Base is supported
Note: Addresses 40h to 7Fh are not defined. All unsupported registers are not writable and will return all zeroes when read. Reserved
registers will also return zeroes when read.
31
16 15
0
Device ID = 0001h
Vendor ID = 1000h
00h
Status
Command
04h
Class Code = 010000h
Rev ID=01h
08h
Not Supported
Header Type
Latency T imer
Cache Line Size
0Ch
Base Address Zero (I/O)*
10h
Base Address One (Memory)**
14h
Not Supported
18h
Not Supported
1Ch
Not Supported
20h
Not Supported
24h
Reserved
28h
Reserved
2Ch
Reserved
30h
Reserved
34h
Reserved
38h
Max_Lat
Min_Gnt
Interrupt Pin
Interrupt Line
3Ch
Figure 3-1: PCI Configuration Register Map