KSZ8041TL-S Micrel Inc, KSZ8041TL-S Datasheet - Page 32

• Manufacturer Part Number: KSZ8041TL-S
• Description: IC TXRX PHY 10/100 BASE 48TQFP
• Manufacturer: Micrel Inc
• Type: Transceiverr

Specifications of KSZ8041TL-S

• Number Of Drivers/receivers: 1/1
• Protocol: SMII
• Voltage - Supply: 3.135 V ~ 3.465 V
• Mounting Type: Surface Mount
• Package / Case: 48-TQFP, 48-VQFP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: 576-3626; KSZ8041TL-S

Micrel, Inc.
HP Auto MDI/MDI-X
HP Auto MDI/MDI-X configuration eliminates the confusion of whether to use a straight cable or a crossover cable
between the KSZ8041TL/FTL/MLL and its link partner. This feature allows the KSZ8041TL/FTL/MLL to use either type of
cable to connect with a link partner that is in either MDI or MDI-X mode. The auto-sense function detects transmit and
receive pairs from the link partner, and then assigns transmit and receive pairs of the KSZ8041TL/FTL/MLL accordingly.
HP Auto MDI/MDI-X is enabled by default. It is disabled by writing a one to register 1F bit 13. MDI and MDI-X mode is
selected by register 1F bit 14 if HP Auto MDI/MDI-X is disabled.
An isolation transformer with symmetrical transmit and receive data paths is recommended to support auto MDI/MDI-X.
The IEEE 802.3 Standard defines MDI and MDI-X as follow:
Straight Cable
A straight cable connects a MDI device to a MDI-X device, or a MDI-X device to a MDI device. The following diagram
depicts a typical straight cable connection between a NIC card (MDI) and a switch, or hub (MDI-X).
December 2009
RJ-45 Pin
Media Dependent Interface
Transmit Pair
Receive Pair
Modular Connector
1
2
3
6
10/100 Ethernet
(RJ-45)
Figure 4. Typical Straight Cable Connection
NIC
MDI
Table 9. MDI/MDI-X Pin Definition
1
2
3
4
5
6
7
8
Signal
RD+
TD+
RD-
TD-
Straight
Cable
32
RJ-45 Pin
1
2
3
6
Media Dependent Interface
(Repeater or Switch)
Modular Connector
1
2
3
4
5
6
7
8
10/100 Ethernet
MDI-X
(RJ-45)
HUB
Transmit Pair
Receive Pair
Signal
RD+
TD+
RD-
TD-
KSZ8041TL/FTL/MLL
M9999-120909-1.2