L-ET4148-50C-DB LSI, L-ET4148-50C-DB Datasheet - Page 267

• Manufacturer Part Number: L-ET4148-50C-DB
• Manufacturer: LSI

Specifications of L-ET4148-50C-DB

• Lead Free Status / RoHS Status: Supplier Unconfirmed

Preliminary Data Sheet
April 2006
Agere Systems Inc.
Appendix B: Configuration
Ethernet Interfaces
Table 378. Port Speed Indications
Autonegotiation (Multispeed Only). Autonegotiation is used to establish the capabilities of the systems at either
end of an Ethernet link. Once the capabilities have been determined, the highest common capability is chosen for
the two link partners to share.
In order to enable autonegotiation, the auto_negotiate_en_{0..9} bit corresponding to the appropriate Ether-
net interface must be asserted.
To manually force the link to renegotiate, the restart_auto_negotiation_{0..9} bit is pulsed (asserted and
then deasserted). The ET4148-50 detects the rising edge of this signal and immediately initiates an autonegotia-
tion session with the corresponding link partner.
SFP Autonegotiation. When ports 44 through 47 are configured to operate in SerDes mode, 1000BASE-X auto-
negotiation is supported.
For revision C, once the SerDes mode is selected and the appropriate auto_negotiate_en_{0..9} bit is asserted,
gmac_rx_pause_en_{}{0..9} and gmac_flow_control_initiate_en_{}{0..9} become the PAUSE
(PS1) and ASM_DIR (PS2) bits, respectively, as defined in Table 37-2 of the IEEE Standard 802.3-2002. Once
autonegotiation is complete, the gmac_rx_pause_en_{}{0..9} and
gmac_flow_control_initiate_en_{}{0..9} bits give the pause priority resolution for PAUSE and
ASM_DIR, respectively, as defined in Table 37-4 of the standard.
Autonegotiation Override (Multispeed Only). If desired, autonegotiation may be disabled and overridden with
manually prescribed parameters. By asserting good_link_force_{0..9}, the supervisor disables autonegotia-
tion and enables the use of speed_mode_force_{0..9}[1:0] and full_duplex_force_{0..9} to set the
port’s operating characteristics.
The full_duplex_force_{0..9} bit is asserted to set the port to operate in full-duplex mode. When deas-
serted, this bit causes the port to operate in half duplex.
The speed_mode_force_{0..9}[1:0] field is used to set the corresponding port to a particular operating
speed. The valid settings are defined in the following table.
Table 379. Port Speed Settings
gmac_port_speed_{0..9}[1:0]
speed_mode_force_{0..9}[1:0]
(continued)
00
01
10
11
00
01
10
11
2
2
2
2
2
2
2
2
Single-Chip 48 x 1 Gbit/s + 2 x 10 Gbits/s Layer 2+ Ethernet Switch
(continued)
Agere Systems - Proprietary
Port Speed
100 Mbits/s
10 Mbits/s
Port Speed
Reserved
100 Mbits/s
10 Mbits/s
Reserved
1 Gbit/s
1 Gbit/s
ET4148-50
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