Fast Ethernet 10/100 Hex Transceiver with Full MII — LXT9763
1.12
Monitoring Operations
1.12.1
Monitoring Auto-Negotiation
Auto-negotiation can be monitored as follows:
• Bit 17.7 is set to 1 once the auto-negotiation process is completed.
• Bits 1.2 and 17.10 are set to 1 once the link is established.
• Additional bits in Register 1 (refer to Table 39 on page 62) and Register 17 (refer to Table 48
on page 68) can be used to determine the link operating conditions and status.
1.12.1.1
Monitoring Next Page Exchange
The LXT9763 offers an Alternate Next Page mode to simplify the next page exchange process.
Normally, bit 6.1 (Page Received) remains set until read. When Alternate Next Page mode is
enabled (16.1 = 1), bit 6.1 is automatically cleared whenever a new negotiation process takes place.
This prevents the user from reading an old value in 6.1 and assuming that Registers 5 and 8
(Partner Ability) contain valid information. Additionally, the LXT9763 uses bit 6.5 to indicate
when the current received page is the base page. This information is useful for recognizing when
next pages must be resent due to a new negotiation process starting. Bits 6.1 and 6.5 are cleared
when read.
1.12.2
Per-Port LED Driver Functions
The LXT9763 incorporates three direct drive LEDs per port. On power up all the LEDs will light
for approximately 1 second after reset de-asserts. Each LED can be programmed to one of several
different display modes using the LED Configuration Register. Each per-port LED can be
programmed (refer to Table 51 on page 71) to indicate one the following conditions:
• Operating Speed
• Transmit Activity
• Receive Activity
• Collision Condition
• Link Status
• Duplex Mode
The LEDs can also be programmed to display various combined status conditions. For example,
setting bits 20.15:12 = 1101 produces the following combination of Link and Activity indications:
• If Link is down LED is off.
• If Link is up LED is on.
• If Link is up AND activity is detected, the LED will blink at the stretch interval selected by
bits 20.3:2 and will continue to blink as long as activity is present.
The LED driver pins are also used to provide initial configuration settings. The LED pins are
sensitive to polarity and will automatically pull up or pull down to configure for either open drain
or open source circuits (10mA max current rating) as required by the hardware configuration. Refer
to the discussion of “Hardware Configuration Settings” on page 23 for details.
Datasheet
35
INTEL [ INTEL ]
