HBLXT9785HE.D0 Intel, HBLXT9785HE.D0 Datasheet - Page 153

• Manufacturer Part Number: HBLXT9785HE.D0
• Manufacturer: Intel

Specifications of HBLXT9785HE.D0

• Lead Free Status / RoHS Status: Not Compliant

LXT9785/LXT9785E
Datasheet
249241, Revision 11.0
16 April 2007
4.12
4.12.1
4.12.2
Cortina Systems
Monitoring Operations
Monitoring Auto-Negotiation
Auto-negotiation may be monitored as follows:
Per-Port LED Driver Functions
The LXT9785/LXT9785E incorporates three direct drive LEDs per port (LEDn_1_L,
LEDn_2_L, and LEDn_3_L).
On power up, all the LEDs lights up for approximately one second after reset de-asserts.
Each LED may be programmed to one of several different display modes using the LED
Configuration Register. Each per-port LED may be programmed (refer to
Configuration Register (Address 20, Hex 14), on page
conditions:
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:
The LED driver pins are open drain circuits (10 mA max current rating). Refer to
5.2.6, LED Circuit, on page 164
design details. The LED Configuration Register also provides optional LED pulse
stretching to 30, 60, or 100 ms. If during this pulse stretch period, the event occurs again,
the pulse stretch time is further extended (see
(Address 20, Hex 14), on page
When an event such as receiving a packet occurs, it is edge detected and starts the
stretch timer. The LED driver remains asserted until the stretch timer expires. If another
event occurs before the stretch timer expires, the stretch timer is reset and the stretch
time extended.
®
• Bits 1.2 and 17.10 = 1 once the link is established.
• Additional bits in Register 1 (refer to
• Operating Speed
• Transmit Activity
• Receive Activity
• Collision Condition
• Link Status
• Duplex Mode
• Isolate Condition
• If Link is down, LED is off.
• If Link is up, LED is on.
• If Link is up AND activity is detected, the LED blinks at the stretch interval selected by
LXT9785 and LXT9785E Advanced 8-Port 10/100 Mbps PHY Transceivers
page
11), on page
bits 20.3:2 and continues to blink as long as activity is present.
193) and Register 17 (refer to
200) can be used to determine the link operating conditions and status.
204).
under the Application Information Section for LED circuit
Table 94, Quick Status Register (Address 17, Hex
Table 85, Status Register (Address 1), on
Table 97, LED Configuration Register
204) to indicate one of the following
4.12 Monitoring Operations
Table 97, LED
Section
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