5-36 361834-002 Technical Reference Guide
Input/Output Interfaces
5.9 Network Interface Controller
These systems provide 10/100/1000 Mbps network support through a Broadcom BCM5751
network interface controller (NIC), a PHY component, and a RJ-45 jack with integral status
LEDs. The 82562-equivalent controller integrated into the 82801 ICH component is not used
(disabled) in these systems. (Figure 5-14). The support firmware for the BCM5782 component
is contained in the system (BIOS) ROM. The NIC can operate in half- or full-duplex modes, and
provides auto-negotiation of both mode and speed. Half-duplex operation features an
Intel-proprietary collision reduction mechanism while full-duplex operation follows the IEEE
802.3x flow control specification.
Figure 5 14. Network Interface Controller Block Diagram
■
The Network Interface Controller includes the following features:
■ Dual high speed RISC controllers with 16-KB caches.
■ Triple-mode support with auto-switching between 10BASE-T, 100BASE-TX, and
1000BASE-T.
■ Power management support for ACPI 1.1, PXE 2.0, WOL, ASF 1.0, IPMI
■ Cable testing capability
■ Link and Activity LED indicator drivers
The controller features high and low priority queues and provides priority-packet processing for
networks that can support that feature. The controller's micro-machine processes transmit and
receive frames independently and concurrently. Receive runt (under-sized) frames are not passed
on as faulty data but discarded by the controller, which also directly handles such errors as
collision detection or data under-run.
The NIC uses 3.3 VDC auxiliary power, which allows the controller to support Wake-On-LAN
(WOL) and Alert-On-LAN (AOL) functions while the main system is powered down.
✎
For the features in the following paragraphs to function as described, the system unit must be
plugged into a live AC outlet. Controlling unit power through a switchable power strip will, with
the strip turned off, disable any wake, alert, or power mangement functionality.
Broadcom
LAN I/F
Green LED
NIC
BCM5751
RJ-45
Connector
Yellow LED
Tx/Rx Data
Tx/Rx Data
LED
Function
Green
Ye l l o w
Activity/Li nk. Indicates network activity and link pulse reception.
Speed. Indicates link detection 100Mb/s mode.
