MT90883 Zarlink Semiconductor, MT90883 Datasheet - Page 59

• Manufacturer Part Number: MT90883
• Description: (MT90880 - MT90883) TDM to Packet Processors
• Manufacturer: Zarlink Semiconductor

Unmatched traffic is also forwarded to the CPU using queue 0. This allows the CPU to analyse the traffic to
work out what should be done with it. Alternatively, if the drop threshold on queue 0 is set very small,
unmatched traffic can be automatically discarded.
6.8.2
The following example shows how to set up the packet classification for a typical expected scenario. The
MT9088x is expecting the following four classes of traffic:
1. TDM traffic using the protocol stack Ethernet - VLAN - CDP
2. TDM traffic using the protocol stack Ethernet - IPv4 - UDP - CDP
3. Data traffic to an external DSP using the protocol stack Ethernet - IPv4 - xxx
4. CPU control traffic using the protocol stack Ethernet - IPv4 - TCP - xxx
5. All other traffic - routed by default to CPU queue 0
Traffic Class 1: Ethernet - VLAN - CDP
Configure the mask and match registers in the packet engine to direct TDM traffic to the WAN interface.
Ethernet/VLAN
Destination MAC address
Source MAC address
Tag Type
VLAN Tag
Length / Type field
Context Descriptor
Version
Context Switch
Context ID[11:7]
Context ID[6:0]
Remainder of the header
Protocol Field
Example Classification Scheme
Table 21 - Pattern Matching for Example Traffic Class 1
Mask
Mask
Allow match
Allow match
Allow match
Allow match
Mask
Allow match
Mask
Mask
Mask
Zarlink Semiconductor Inc.
MT90880/1/2/3
If the MAC block is programmed into promiscuous
mode then the destination MAC address must be
matched,
Must be 0x8100
Must be set to the appropriate value for TDM traffic.
Must be set to the appropriate type for TDM traffic. Will
require allocation of an Ethertype by the IEEE.
Must be 0b000
Must be 0b00000
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