103
Tsi578 User Manual
June 6, 2016
Integrated Device Technology
www.idt.com
5. Multicast
This chapter describes the multicast features of the Tsi578. It includes the following information:
•
•
“Multicast Behavior Overview” on page 106
•
“Multicast Group Tables” on page 110
•
“Multicast Work Queue” on page 107
•
“Broadcast Buffers” on page 107
•
“Error Management of Multicast Packets” on page 118
•
5.1
Overview
The Tsi578 multicast functionality is compliant to the
RapidIO Version 1.3 Part 11 Multicast
Specification
.
5.1.1
Multicast Operation
In a multicast operation, packets are received at the speed of any ingress port (up to 10 Gbits/s) and
broadcast at the speed of the egress ports (up to 10 Gbits/s for a 4x mode port operating at
3.125 Gbits/s) to multiple ports capable of accepting packets for transmission. The maximum amount
of data that can be transmitted by the switch is 70 Gbits/s for seven egress ports operating at maximum
width of 4x and a lane speed of of 3.125 Gbit/s, based on the the number of ports on the Tsi578.
Packets are routed to the multicast engine based on their destinationID and Transaction Type (TT) field
value. If no match is found for the destinationID and TT field, then the ingress lookup tables are used to
route the packet. A maximum of eight different DestID/TT field combinations can be routed to the
multicast engine. Each destinationID/TT set can be multicast to a different set of egress ports. A set of
egress ports that packets are multicast to is called a multicast group and is represented by the multicast
mask in the group table. A multicast packet is never sent out on the port that it was received on. Any
number of ports can share the same multicast group.
Multicast packets are accepted by egress ports based on priority. In the event that multicast and unicast
traffic are competing for resources in the egress port, multicast specific egress arbitration can be used
to favour multicast or unicast traffic. This allows a group of endpoints that need to multicast to each
other to share the same multicast mask.
5.1.2
Features
The Tsi578 supports multicast packet replication in accordance with
RapidIO Specification Version
1.3, Part 11 Multicast
.