Revision 1.02 – April 12, 2007
S5920 – PCI Product: Initialization
Data Book
A 16-bit pointer at location 18h of the PC expansion
ROM identifies the start offset of the PCI data struc-
ture. The PCI data structure is shown in Table 3 and
contains various vendor, product, and program
descriptions. This structure is provided here for refer-
ence only - the user should refer to the PCI BIOS
specification for complete details.
Note: The access time for large serial devices should
be considered, since it may cause a lengthy system
delay during initialization. For example, a 2 Kbytes
serial device will take about 1 second to be read. Many
systems, even when BIOS ROMs are ultimately shad-
owed into system RAM, may read this memory space
twice (once to validate its size and checksum, and
once to move it into RAM).
Table 51. PCI Data Structure
Byte Length
(decimal)
Byte Offset
Binary Value
Description
0h
4
ÔPCIRÕ
Signature, the ASCII string ÔPCIRÕ where ÔPÕ is at offset 0, ÔCÕ at off-
set 1, and so on
4h
6h
2
2
2
2
1
3
2
2
2
1
2
variable
variable
variable
variable
variable
variable
variable
variable
variable
variable
0000h
Vendor Identification
Device Identification
8h
Pointer to Vital Product Data
PCI Data Structure Length (starts with signature field)
PCI Data Structure Revision (=0 for this definition)
Class Code
Ah
Ch
Dh
10h
12h
14h
15h
16h
Image Length
Revision Level
Code Type
Indicator (bit D7=1 signifies “last image”)
Reserved
AMCC Confidential and Proprietary
DS1596
101
AMCC [ APPLIED MICRO CIRCUITS CORPORATION ]
