Subsystem id, Registers: 0x2e–0x2f – LSI 53C875A User Manual
Page 103
PCI Configuration Registers
4-11
controller installed on them (and therefore the same
Vendor ID and Device ID).
If the external serial EEPROM interface is enabled
(MAD[7] LOW), this register is automatically loaded at
power-up from the external serial EEPROM and will
contain the value downloaded from the serial EEPROM
or a value of 0x0000 if the download fails.
If the external serial EEPROM interface is disabled
(MAD[7] HIGH), this register returns a value of 0x1000
(LSI Logic Vendor ID). The 16-bit value that should be
stored in the external serial EEPROM for this register is
the vendor’s PCI Vendor ID and must be obtained from
the PCI Special Interest Group (SIG). Please see
2.4, “Serial EEPROM Interface,”
in
for more
information on downloading a value for this register.
Registers: 0x2E–0x2F
Subsystem ID
Read Only
SID
Subsystem ID
[15:0]
This 16-bit register is used to uniquely identify the add-in
board or subsystem where this PCI device resides. It
provides a mechanism for an add-in card vendor to
distinguish its cards from one another even if the cards
have the same PCI controller installed on them (and
therefore the same Vendor ID and Device ID).
If the external serial EEPROM interface is enabled
(MAD[7] is LOW), this register is automatically loaded at
power-up from the external serial EEPROM and will
contain the value downloaded from the serial EEPROM
or a value of 0x0000 if the download fails.
If the external serial EEPROM is disabled (MAD[7] pulled
HIGH), the register returns a value of 0x1000. The 16-bit
15
0
SID
If MAD[7] HIGH Default
0
0
0
1
0
0
0
0
0
0
0
0
0
0
0
0
If MAD[7] LOW See Description Default
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x