adm6996f Infineon Technologies Corporation, adm6996f Datasheet - Page 23

• Manufacturer Part Number: adm6996f
• Description: 6 Port 10/100 Mb/s Single Chip Ethernet Switch Controller
• Manufacturer: Infineon Technologies Corporation

ADM6996F
Infineon-ADMtek Co Ltd.
3.4.12 Far-End Fault
3.5
3.5.1 Transmit Drivers
3.5.2 Twisted-Pair Receiver
3.6
Auto negotiation provides a mechanism for transferring information from the Local
Station to the link Partner that a remote fault has occurred for 100Base-TX. As auto
negotiation is not currently specified for operation over fiber, the far end fault indication
function (FEFI) provides this capability for 100Base-FX applications.
A remote fault is an error in the link that one station can detect while the other cannot. An
example of this is a disconnected wire at a station’s transmitter. This station will be
receiving valid data and detect that the link is good via the link integrity monitor, but will
not be able to detect that its transmission is not propagating to the other station.
A 100Base-FX station that detects such a remote fault may modify its transmitted idle
stream from all ones to a group of 84 ones followed by a single 0. This is referred to as
the FEFI idle pattern.
100Base-TX Transceiver
ADM6996F implements a TP-PMD compliant transceiver for 100Base-TX operation.
The differential transmit driver is shared by the 10Base-T and 100Base-TX subsystems.
This arrangement results in one device that uses the same external magnetic for both the
10Base-T and the 100Base-TX transmission with simple RC component connections.
The individually wave-shaped 10Base-T and 100Base-TX transmit signals are
multiplexed in the transmission output driver selection.
The ADM6996F 100Base-TX transmission driver implements MLT-3 translation and
wave-shaping functions. The rise/fall time of the output signal is closely controlled to
conform to the target range specified in the ANSI TP-PMD standard.
For 100Base-TX operation, the incoming signal is detected by the on-chip twisted-pair
receiver that consists of a differential line receiver, an adaptive equalizer and a base-line
wander compensation circuits.
The ADM6996F uses an adaptive equalizer that changes filter frequency response in
accordance with cable length. The cable length is estimated based on the incoming signal
strength. The equalizer tunes itself automatically for any cable length to compensate for
the amplitude and phase distortions incurred from the cable.
10Base-T Module
The 10Base-T Transceiver Module is IEEE 802.3 compliant. It includes the receiver,
transmitter, collision, heartbeat, loop back, jabber, wave shaper, and link integrity
Function Description
3-5