lan9218i Standard Microsystems Corp., lan9218i Datasheet - Page 64

• Manufacturer Part Number: lan9218i
• Description: Lan9218i High-performance Single-chip 10/100 Ethernet Controller With Hp Auto-mdix And Industrial Temperature Support
• Manufacturer: Standard Microsystems Corp.

Revision 2.3 (08-06-08)
4.8
Auto-Negotiation
Auto-Negotiation
Auto-Negotiation
Auto-Negotiation
Auto-Negotiation
Auto-Negotiation
Auto-Negotiation
Auto-Negotiation
Manual
Manual
Manual
Manual
Manual
Manual
Manual
Manual
MODE
Note 4.1
HP Auto-MDIX facilitates the use of CAT-3 (10 Base-T) or CAT-5 (100 Base-T) media UTP interconnect
cable without consideration of interface wiring scheme. If a user plugs in either a direct connect LAN
cable, or a cross-over patch cable, as shown in
capable of configuring the TPO and TPI twisted pair pins for correct transceiver operation.
The internal logic of the device detects the TX and RX pins of the connecting device. Since the RX
and TX line pairs are interchangeable, special PCB design considerations are needed to accommodate
the symmetrical magnetics and termination of an Auto-MDIX design.
The Auto-MDIX function can be disabled through an internal register 27.15, or the external control pins
AMDIX_EN. When disabled the TX and RX pins can be configured with the Channel Select
(CH_SELECT) pin as desired.
HP Auto-MDIX
The LAN9218i 10/100 PHY internal CRS signal operates in two modes: Active and Low.
When in Active mode, the internal CRS will transition high and low upon line activity, where
a high value indicates a carrier has been detected. In Low mode, the internal CRS stays
low and does not indicate carrier detection. The internal CRS signal and No Carrier (bit 10
of the TX Status word) cannot be used as a verification method of transmitted packets
when transmitting in 10/100 Mbps full-duplex mode.
100 Mbps
100 Mbps
100 Mbps
100 Mbps
100 Mbps
100 Mbps
100 Mbps
100 Mbps
10 Mbps
10 Mbps
10 Mbps
10 Mbps
10 Mbps
10 Mbps
10 Mbps
10 Mbps
SPEED
High-Performance Single-Chip 10/100 Ethernet Controller with HP Auto-MDIX and Industrial Temperature Support
Table 4.2 CRS Behavior
DATASHEET
Half-Duplex
Half-Duplex
Half-Duplex
Half-Duplex
Half-Duplex
Half-Duplex
Half-Duplex
Half-Duplex
Full-Duplex
Full-Duplex
Full-Duplex
Full-Duplex
Full-Duplex
Full-Duplex
Full-Duplex
Full-Duplex
DUPLEX
64
Figure
4.3, the SMSC LAN9218i Auto-MDIX PHY is
Transmitting
Transmitting
Transmitting
Transmitting
Transmitting
Transmitting
Transmitting
Transmitting
ACTIVITY
Receiving
Receiving
Receiving
Receiving
Receiving
Receiving
Receiving
Receiving
CRS BEHAVIOR
(Note
Active
Active
Active
Active
Active
Active
Active
Active
Active
Active
Active
Active
Low
Low
Low
Low
SMSC LAN9218i
4.1)
Datasheet