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Cortina Systems LXT9785 and LXT9785E Advanced 8-Port 10/100 Mbps PHY Transceivers
LXT9785/LXT9785E
Datasheet
249241, Revision 11.0
16 April 2007
4.11 DTE Discovery Process
Figure 30
Cortina Systems LXT9785E Negotiation Flow Chart
Default Mode
Transmit based upon hardware
configuration
FLP, NLP or IDLE Symbols
Power Up
or
Link Down 1.2 = 0 and Dis_EN 27.6 = 0
or
Link Down 1.2 = 0 and Forced Mode
Software Intervention
Auto-negotiation 0.12 = 1 (if needed)
Power_EN 27.6 = 1
Discovery Base
Transmit FLPs
Base Page (Register 4)
with Next Page 4.15 = 1
FLP Detected
Next Page
Set?
No
Auto Negotiation
Determine Compatibility Options
FLP Detected
LFIT Expired 27.2 = 1
Dis_EN 27.6 = 1
LFIT Expired 27.2 = 1
Dis_EN 27.6 = 0
NLPs or IDLE Symbols
Detected
Yes
Next Page Transmission
Use Random Data for User Defined
Bits as Code
Next Pages Received
Pages = Code
Transmitted?
No
Parallel Detection
Determine Compatibility on
Speed and Duplex
Check Advertisement
NLPs or IDLE Symbols
Detected
Yes
DTE Discovered
Transmit Last Page Continuously
Power_EN 27.4 = 1
Software Intervention
Software Polled Power_EN 27.4 = 1
Turn On Power Supply
Link Up
Compatibility
LFIT Expired 27.2 = 1
Dis_EN 27.6 = 1
Compatibility
Power On
Wait State for
Proper Power
Assertiion
Set Mode
Restart
Auto-Negotiation
or
Force Speed
Auto-
Negotiation?
Yes
No
Assumptions:
Auto-Negotiation/Forced Speed Set by Pins
Advertisement Requirements Set by Pins
LFIT Expired 27.2 = 1
Link Fail Timeout = 1
Dis_EN Not Set 27.6 = 0
Start
Link Down 1.2 = 0
and
Dis_EN 27.6 = 1
and
Auto-Neg 0.12 = 1
Power Applied
Nonmatching DTE
Discovery NP
Received