VSC8641XKO Vitesse Semiconductor Corp, VSC8641XKO Datasheet - Page 23

• Manufacturer Part Number: VSC8641XKO
• Description: IC PHY 10/100/1000 100-LQFP
• Manufacturer: Vitesse Semiconductor Corp
• Type: PHY Transceiverr

Specifications of VSC8641XKO

• Number Of Drivers/receivers: 1/1
• Protocol: Gigabit Ethernet
• Voltage - Supply: 2.5V, 3.3V
• Mounting Type: Surface Mount
• Package / Case: 100-LQFP
• Case: TQFP
• Dc: 07+
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: 907-1031

Figure 6.
3.4
Revision 4.3
August 2009
SimpliPHY
TXVN_A_n
TXVN_B_n
TXVP_C_n
TXVN_C_n
TXVP_D_n
TXVN_D_n
TXVP_A_n
TXVP_B_n
Cat5 Media Interface
Cat5 Auto-Negotiation
The VSC8641 device supports twisted pair auto-negotiation as defined by clause 28 of
the IEEE standard 802.3-2000.
The auto-negotiation process consists of the evaluation of the advertised capabilities of
the PHY and its link partner to determine the best possible operating mode, throughput
speed, duplex configuration, and master or slave operating modes in the case of
1000BASE-T setups. Auto-negotiation also allows a connected MAC to communicate
with its link partner MAC through the VSC8641 device using the optional “next pages,”
which set attributes that may not otherwise be defined by the IEEE standard.
In installations where the Cat5 link partner does not support auto-negotiation, the
VSC8641 automatically switches to use parallel detection to select the appropriate link
speed.
Clearing VSC8641 device register 0, bit 12 disables clause 28 twisted-pair auto-
negotiation. If auto-negotiation is disabled, the state of register bits 0.6, 0.13, and 0.8
determine the device operating speed and duplex mode. For more information about
configuring auto-negotiation, see
0.1 µF
0.1 µF
0.1 µF
0.1 µF
“IEEE Standard and Main Registers,”
Transformer
Functional Descriptions
VSC8641 Datasheet
75
75
75
75
page 41.
1
2
3
6
4
5
7
8
A+
A-
B+
B-
C+
C-
D+
D-
1000pF, 2kV
RJ-45
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