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Datasheet
53
Networkin
g
Silicon — GD82559ER
7.1.10 PCI Subs
y
stem Vendor ID and Subs
y
stem ID Re
g
isters
The Subsystem Vendor ID field identifies the vendor of an 82559ER-based solution. The
Subsystem Vendor ID values are based upon the vendor’s PCI Vendor ID and is controlled by the
PCI Special Interest Group (SIG).
The Subsystem ID field identifies the 82559ER-based specific solution implemented by the vendor
indicated in the Subsystem Vendor ID field.
The 82559ER provides support for configurable Subsystem Vendor ID and Subsystem ID fields.
After hardware reset is de-asserted, the 82559ER automatically reads addresses Ah through Ch of
the EEPROM. The first of these 16-bit values is used for controlling various 82559ER functions.
The second is the Subsystem ID value, and the third is the Subsystem Vendor ID value. Again, the
default values for the Subsystem ID and Subsystem Vendor ID are 0h and 0H, respectively.
The 82559ER checks bit numbers 15, 14, and 13 in the EEPROM, word Ah and functions
according to Table 7 below.
Note:
The Revision ID is subject to change according to the silicon stepping.
The above table implies that if the 82559ER detects the presence of an EEPROM (as indicated by a
value of 01b in bits 15 and 14), then bit number 13 determines whether the values read from the
EEPROM, words Bh and CH, will be loaded into the Subsystem ID (word BH) and Subsystem
Vendor ID (word CH) fields. If bits 15 and 14 equal 01b and bit 13 equals 1b, the three least
significant bits of the Revision ID field are programmed by bits 8-10 of the first EEPROM word,
word AH.
Between the de-assertion of reset and the completion of the automatic EEPROM read, the
82559ER does not respond to any PCI configuration cycles. If the 82559ER happens to be accessed
during this time, it will Retry the access. More information on Retry is provided in Section
4.2.1.1.3, “Retry Premature Accesses” on page 17.
7.1.11 Ca
p
abilit
y
Pointer
The Capability Pointer is a hard coded byte register with a value of DCH. It provides an offset
within the Configuration Space for the location of the Power Management registers.
7.1.12 Interru
p
t Line Re
g
ister
The Interrupt Line register identifies which system interrupt request line on the interrupt contoller
the device’s PCI interrupt request pin (as defined in the Interrupt Pin register) is routed to.
Table 7. 82559ER ID Fields Pro
g
rammin
g
Bits 15, 14 Bit 13 Device ID Vendor ID Revision ID Subsystem ID
Subsystem
Vendor ID
11b, 10b,
00b
X 1209H 8086H 09H 0000H
(
Default
)
0000H
(
Default
)
01b 0b 1209H 8086H 09H Word BH Word CH
01b 1b 1209H 8086H Word AH,
bits 10:8
Word BH Word CH