
IDT Multicast
PES32NT24xG2 User Manual
17 - 9
January 30, 2013
Notes
perform NT multicast egress processing (see section NT Multicast Egress Processing on page 17-9) and
transmit the TLP on their data-link. The determination of which ports transmit the TLP is based on the
following:
–
The received TLP’s multicast group ID.
–
The programming of the NT Multicast Group x Port Association (NTMCG[3:0]PA) registers,
located in the configuration space of the NT function in the partition.
–
The setting of the NT Multicast Transmit Enable (NTMCTEN) bit in NT Multicast Control (NTMCC)
register of the switch egress port(s).
On reception of a multicast TLP, the receiving port computes the multicast group ID of the TLP, checks
the appropriate NT Multicast Group Port Association register to determine the egress port(s) associated
with that group ID, and sends the TLPs to these egress ports.
Associated with each egress port in the switch is an NT Multicast Control (NTMCC) register. When the
NT Multicast Transmit Enable (NTMCTEN) bit is set in this register, the egress port is enabled for transmis-
sion of NT multicast TLPs. Otherwise, the port does not transmit NT multicast TLPs, even if the port is part
of an NT multicast group.
For egress ports enabled for NT multicast transmission, the NT multicast TLP logically emerges at the
data-link layer of these ports. Therefore, none of the legacy PCI control bits have effect on the TLP (e.g.,
the Memory Access Enable (MAE) or Bus Master Enable (BME) bits at the egress port’s PCICMD register
have no effect on NT multicast TLPs). The only processing performed by an egress port on NT multicast
TLPs is the processing described in section NT Multicast Egress Processing on page 17-9.
The NT Multicast Group x Port Association (NTMCG[3:0]PA) registers create an association between
the multicast group ID of the received TLP and the egress switch ports to which the NT multicast TLP is
forwarded.
–
NT Multicast is only supported for multicast group IDs 0, 1, 2, and 3.
Each NT Multicast Group x Port Association register corresponds to a multicast group ID (e.g.,
NTMCG[0]PA corresponds to group 0, NTMCG[1]PA corresponds to group 1, etc.). Each NTMCGxPA
register may be programmed to select zero or more ports associated with the corresponding multicast
group. Refer to the definition of the NTMCG[3:0]PA registers for details.
–
The NTMCGxPA registers must be programmed with ports that are associated with other parti-
tions. These registers must not be programmed with ports that are in the same partition as the NT
function that receives the NT multicast TLP. Violation of this rule produces undefined results.
–
When the NTMCGxPA register is programmed to select zero ports, multicast TLPs associated
with the corresponding group ID are silently dropped by the NT function.
Note that by configuring the multicast groups in the PCI-to-PCI bridge and NT functions appropriately, it
is possible that a received TLP be simultaneously multicasted within the partition (i.e., transparent multi-
cast) and across partitions (NT multicast).
NT Multicast Egress Processing
PES32NT24xG2 ports perform NT multicast egress processing, which consists of address and
requester ID overlay, prior to transmitting the NT multicast TLP on the data-link. NT multicast address and
requester ID overlay processing is performed independently by each port. Therefore, it is possible to
configure this functionality independently for each port. Furthermore, within a port, NT multicast address
overlay and requester ID overlay may be independently enabled.
–
NT multicast address overlay is enabled via the NTMCAOE bit in the NT Multicast Control
(NTMCC) register.
–
NT multicast address overlay is enabled via the NTMCRIDOE bit in the NT Multicast Control
(NTMCC) register.
NT multicast egress processing is performed by the port, and not by a specific function in the port.
Therefore, the egress port need not contain an NT function in order to perform NT multicast egress
processing. Further, the egress port need not be in a partition that contains an NT function
1
.
Summary of Contents for PCI Express 89HPES32NT24xG2
Page 20: ...IDT Table of Contents PES32NT24xG2 User Manual x January 30 2013 Notes...
Page 24: ...IDT List of Tables PES32NT24xG2 User Manual xiv January 30 2013 Notes...
Page 28: ...IDT List of Figures PES32NT24xG2 User Manual xviii January 30 2013 Notes...
Page 56: ...IDT PES32NT24xG2 Device Overview PES32NT24xG2 User Manual 1 20 January 30 2013 Notes...
Page 100: ...IDT Switch Core PES32NT24xG2 User Manual 4 22 January 30 2013 Notes...
Page 128: ...IDT Failover PES32NT24xG2 User Manual 6 4 January 30 2013 Notes...
Page 148: ...IDT Link Operation PES32NT24xG2 User Manual 7 20 January 30 2013 Notes...
Page 164: ...IDT SerDes PES32NT24xG2 User Manual 8 16 January 30 2013 Notes...
Page 170: ...IDT Power Management PES32NT24xG2 User Manual 9 6 January 30 2013 Notes...
Page 196: ...IDT Transparent Switch Operation PES32NT24xG2 User Manual 10 26 January 30 2013 Notes...
Page 244: ...IDT SMBus Interfaces PES32NT24xG2 User Manual 12 40 January 30 2013 Notes...
Page 247: ...IDT General Purpose I O PES32NT24xG2 User Manual 13 3 January 30 2013 Notes...
Page 248: ...IDT General Purpose I O PES32NT24xG2 User Manual 13 4 January 30 2013 Notes...
Page 330: ...IDT Switch Events PES32NT24xG2 User Manual 16 6 January 30 2013 Notes...
Page 342: ...IDT Multicast PES32NT24xG2 User Manual 17 12 January 30 2013 Notes...
Page 344: ...IDT Temperature Sensor PES32NT24xG2 User Manual 18 2 January 30 2013 Notes...
Page 384: ...IDT Register Organization PES32NT24xG2 User Manual 19 40 January 30 2013...
Page 492: ...IDT Proprietary Port Specific Registers PES32NT24xG2 User Manual 21 44 January 30 2013 Notes...
Page 588: ...IDT NT Endpoint Registers PES32NT24xG2 User Manual 22 96 January 30 2013 Notes...
Page 710: ...IDT JTAG Boundary Scan PES32NT24xG2 User Manual 25 12 January 30 2013 Notes...
Page 743: ...IDT Usage Models PES32NT24xG2 User Manual 26 33 January 30 2013 Notes...
Page 744: ...IDT Usage Models PES32NT24xG2 User Manual 26 34 January 30 2013 Notes...