876784 Intel, 876784 Datasheet - Page 326

• Manufacturer Part Number: 876784
• Manufacturer: Intel

Specifications of 876784

• Lead Free Status / RoHS Status: Compliant

8.2.12
8.2.13
326
GENSTA—General Status Register
(LAN Controller—B1:D8:F0)
Offset Address: 1Dh
Default Value:
SMB_PCI—SMB via PCI Register
(LAN Controller—B1:D8:F0)
Offset Address: 1Fh
Default Value:
Software asserts SREQ when it wants to isolate the PCI-accessible SMBus to the ASF
registers/commands. It waits for SGNT to be asserted. At this point SCLI, SDAO, SCLO,
and SDAI can be toggled/read to force ASF controller SMBus transactions without
affecting the external SMBus. After all operations are completed, the bus is returned to
idle (SCLO=1b,SDAO=1b, SCLI=1b, SDAI=1b), SREQ is released (written 0b). Then
SGNT goes low to indicate released control of the bus. The logic in the ASF controller
only asserts or deasserts SGNT at times when it determines that it is safe to switch (all
SMBuses that are switched in/out are idle).
When in isolation mode (SGNT=1), software can access the ICH7 SMBus slaves that
allow configuration without affecting the external SMBus. This includes configuration
register accesses and ASF command accesses. However, this capability is not available
to the external TCO controller. When SGNT=0, the bit-banging and reads are reflected
on the main SMBus and the PCISML_SDA0, PCISML_SCL0 read only bits.
7:3
Bit
7:6
Bit
2
1
0
5
4
3
2
1
0
Reserved
Duplex Mode — RO. This bit indicates the wire duplex mode.
0 = Half duplex
1 = Full duplex
Speed — RO. This bit indicates the wire speed.
0 = 10 Mb/s
1 = 100 Mb/s
Link Status Indication — RO. This bit indicates the status of the link.
0 = Invalid
1 = Valid
Reserved
PCISML_SCLO
PCISML_SGNT
PCISML_SREQ
PCISML_SDAO
PCISML_SDAI
PCISML_SCLI
00h
27h
—
—
—
—
—
—
R/W. SMBus Clock to the ASF controller.
R/W. SMBus Data to the ASF controller.
RO. SMBus Clock from the ASF controller.
R/W. SMBus Isolation Request to the ASF controller.
RO. SMBus Isolation Grant from the ASF controller.
RO. SMBus Data from the ASF controller.
LAN Controller Registers (B1:D8:F0) (Desktop and Mobile Only)
Description
Description
Attribute:
Size:
Attribute:
Size:
Intel
RO
8 bits
R/W, RO
8 bits
®
ICH7 Family Datasheet