I347-AT4 Datasheet, PDF (31/148 Pages) Intel Corporation – Intel® Ethernet Network Connection I347-AT4 Datasheet

Device Functionality—I347-AT4
3.2.6
Table 9.
SGMII Speed and Link
When the SGMII MAC interface is used, the interface is copper . The operational speed
of the SGMII MAC interface is determined according to Table 9 media interface status
and/or loopback mode.
SGMII (MAC Interface) Operational Speed
Link Status or Media Interface Status
No Link
MAC Loopback
SGMII (MAC Interface) Speed
Determined by speed setting of 21_2.2:0
Determined by speed setting of 21_2.2:0
3.2.7
3.3
SGMII TRR Blocking
When the SGMII receives a packet with odd number of bytes, a single symbol of carrier
extension will be passed on and transmitted onto 1000BASE-T. This carrier extension
may cause problems with full-duplex MACs that incorrectly handle the carrier extension
symbols. When register 16_1.13 is set to 1, all carrier extend and carrier extend with
error symbols received by the SGMII will be converted to idle symbols when operating
in full-duplex. Carrier extend and carrier extend with error symbols will not be blocked
when operating in half-duplex, or if register 16_1.13 is set to 0b. Note that symbol
errors will continue to be propagated regardless of the setting of register 16_1.13.
This function is on by default as the SGMII rev 1.8 standard requires this function to be
implemented.
Loopback
The I347-AT4 implements various different loopback paths.
3.3.1
System Interface Loopback
The functionality, timing, and signal integrity of the system interface can be tested by
placing the I347-AT4 in system interface loopback mode. This can be accomplished by
setting register 0_0.14 = 1b, 0_1.14 = 1b, or 0_4.14 = 1b. In loopback mode, the data
received from the MAC is not transmitted out on the media interface. Instead, the data
is looped back and sent to the MAC. During loopback, link will be lost and packets will
not be received.
If loopback is enabled while auto-negotiating, FLP auto-negotiation codes will be
transmitted. If loopback is enabled in forced 10BASE-T mode, 10BASE-T idle link pulses
will be transmitted on the copper side. If loopback is enabled in forced 100BASE-T
mode, 100BASE-T idles will be transmitted on the copper side.
The speed of the SGMII interface is determined by register 21_2.2:0 during loopback.
21_2.2:0 is 100b = 10 Mb/s, 101b = 100 Mb/s, 110b = 1000 Mb/s.
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