5 Host Messaging and System
Configuration
The 4450 supports in-band and out-of-band host messaging for the purpose of system boot
and initialization, SPD & SAD management and exception handling, as well as IP packet
fragment reassembly.
5.1 Gigabit Ethernet & RMII Host Interfaces
The two Host side Gigabit Ethernet Interfaces (host 0 and host 1) can be configured for
either GMII/RGMII/SGMII/TBI/RTBI/SerDes signalling to accommodate data
communications between the host based MAC and the 4450. The interface signally options
for both host 0 and host 1 are configured to the same signalling option (i.e., GMII, RGMII,
etc.) for each host port. The Gigabit Ethernet Interfaces may also be used for in-band 4450
to host communications. The 4450 supports an additional RMII interface that can be used
for out-of-band host communications, messaging and management of the 4450. Figure 5-1
shows an example of the 4450 system connections.
DDR2 SDRAM
SerDes
4450
RGMII
RTBI/
SGMI/
GMIII/
TBI
(SA’s & IKE)
SerDes
RGMII
RTBI/
SGMII
Dual GigE TOE
or
SFP
SFP
Storage
Processor
with Integrated
GigE MAC
SerDes
RGMII
RTBI/
SGMII
SerDes
RGMII
RTBI/
SGM II/
GMII/
TBI
0.75V
1.5V
1.0V
2.5V
3.3V
PCI-X
or
PCI -Express
Voltage
Regulation
Osc.
Figure 5-1. Example 4450 System Connection
4450 – Data Sheet, DS-0131-06
Page27
Hifn Confidential
EXAR [ EXAR CORPORATION ]
