ADM6996L-AA-T-1 Lantiq, ADM6996L-AA-T-1 Datasheet - Page 22

• Manufacturer Part Number: ADM6996L-AA-T-1
• Manufacturer: Lantiq

Specifications of ADM6996L-AA-T-1

• Lead Free Status / RoHS Status: Supplier Unconfirmed

1. If the SA was not found in the Address Table (a new address), the ADM6996L/LX waits until the end of the
2. When the DA is PAUSE command, then the learning process will be disabled automatically by ADM6996L/LX.
3.15.2
The ADM6996L/LX forwards the incoming packets between bridged ports according to the Destination Address
(DA) as below. All the packet forwarded will check the VLAN first. A forwarding port must be the within the same
VLAN as the source port.
If the DA is a UNICAST address and the address was found in the Address Table, the ADM6996L/LX will check
the port number and act as follows:
•
•
•
•
•
•
3.15.3
Address aging is supported for topology changes such as an address moving from one port to another. When this
happens, the ADM6996L/LX internally has a 300 second timer which will “age-out” (remove) the address from the
address table. The aging function can be enabled/disabled by the user. Normally, disabling an aging function is
for security purposes.
3.15.4
The ADM6996L/LX implements the truncated exponential back off algorithm compliant to the 802.3 CSMA-CD
standard. The ADM6996L/LX will restart the back off algorithm by choosing 0-9 collision counts. The
ADM6996L/LX resets the collision counter after 16 consecutive retransmit trials.
3.15.5
IPG is the idle time between any two successive packets from the same port. The typical number is 96 bits at a
time. The value is 9.6 micro secs for 10Mbps ETHERNET, 960ns for 100Mbps fast ETHERNET and 96ns for
1000M. The ADM6996L/LX provides an option of 92 bit gap in an EEPROM to prevent packet loss when Flow
Control is turned off and clock P.P.M. values differ.
3.15.6
The ADM6996L/LX will discard all illegal frames such as runt packets (less than 64 bytes), oversized packets
(greater than 1518 or 1522 bytes) and bad CRC. Dribbling packing with good CRC value will be accepted by the
ADM6996L/LX. In case of bypass mode enable, the ADM6996L/LX will support tag and untagged packets with
sizes up to 1522 bytes. In case of non-bypass mode, the ADM6996L/LX will support tag packets up to 1526bytes
and untagged packets up to 1522bytes.
3.15.7
A back pressure function is supported for half-duplex operations. When the ADM6996L/LX cannot allocate a
receive buffer for an incoming packet (buffer full), the device will transmit a jam pattern on the port, thus forcing a
collision. Back Pressure is enabled by the BPEN set during RESET assertion. An Infineon proprietary algorithm is
Data Sheet
packet (non-error packet) and updates the Address Table. If the SA was found in the Address Table, then the
aging value of each corresponding entry will be reset to 0
If the port number is equal to the port on which the packet was received, the packet is discarded.
If the port number is different, the packet is forwarded across the bridge.
If the DA is a UNICAST address and the address was not found, the ADM6996L/LX treats it as a multicast
packet and forwards it across the bridge.
If the DA is a Multicast address, the packet is forwarded across the bridge.
If the DA is a PAUSE Command (01-80-C2-00-00-01), then this packet will be dropped by the ADM6996L/LX.
The ADM6996L/LX can issue and learn PAUSE commands.
The ADM6996L/LX will forward the packet with a DA of (01 80 C2 00 00 00
of (01 80 C2 00 00 01
Address Recognition and Packet Forwarding
Address Aging
Back off Algorithm
Inter-Packet Gap (IPG)
Illegal Frames
Half Duplex Flow Control
H
), and forward a packet with a DA of (01-80-C2-00-00-02
22
B
.
H
), filter out the packet with a DA
H
to 01 80 C2 00 00 0F
Function Description
Rev. 1.13, 2005-11-22
ADM6996L/LX
Data Sheet
H
)