GR740-UM-DS, Nov 2017, Version 1.7
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can be enabled for both physical and logical addresses and is configured by programming the corre-
sponding RTR.RTPMAP register.
When a packet arrives and group adaptive routing is enabled for the packet's address, the router looks
up the group of ports selected by the corresponding RTR.RTPMAP register and transmits the packet
on the port with the lowest index that is currently ready. Ready in this context means that the port's
link interface is in run-state and currently not sending any other packet. If none of the selected output
ports is ready, the incoming packet will either be spilled or transmitted on the first port that becomes
ready. The action taken depends on the setting of the input port’s data character timer (see section
13.2.15), the spill-if-not-ready feature for the address (see section 13.2.10), and the link-start-on-
request feature for the output ports (see section 13.2.13). See table 175 in section 13.5.3 for details on
how to enable and configure group adaptive routing.
13.2.7 Packet distribution
Packet distribution can be used to implement multicast and broadcast addresses and can be enabled
for both physical and logical addresses. Packet distribution is enabled and configured by program-
ming the corresponding RTR.RTPMAP register.
When a packet arrives and packet distribution is enabled for the packet’s address, the router looks up
the group of ports selected by the corresponding RTR.RTPMAP register. If all of the selected ports are
ready, the packet is transmitted on all the ports. Ready in this context means that the port’s link inter-
face is in run-state and currently not sending any other packet. If one or more of the selected ports are
not ready, the incoming packet will either be spilled or transmitted once all ports are ready. The action
taken depends on the setting of the input port’s data character timer (section 13.2.15), the spill-if-not-
ready feature for the address (section 13.2.10), and the link-start-on-request feature for the output
ports (section 13.2.13). See table 175 in section 13.5.3 for details on how to enable and configure
packet distribution.
13.2.8 Port disable
A port can be disabled for data traffic by setting the corresponding RTR.PCTRL.DI bit. Incoming
packets on a disabled port are silently spilled and packets are never routed to disabled ports. A dis-
abled port will therefore not be included in any group used for group adaptive routing or packet distri-
bution, even if the corresponding bit in that address’ RTR.RTPMAP.PE field is set.
The RTR.PCTRL.DI bit only affects the routing of data and is therefore not affecting the transmission
and reception of time-codes and distributed interrupt codes.
13.2.9 Static routing
The router supports a feature called static routing, which can be enabled for each port individually.
When enabled, all incoming packets on the port are routed based on the physical address specified in
the port’s RTR.PCTRL2.SC field and the setting of the corresponding RTR.PCTRL2.SC bit rather
than on the addresses of the packets. Header deletion is not used for incoming packets if static routing
is enabled, which means that the first byte of the packets is always sent to the output port as well.
Static routing to port 0 is not allowed and generates an invalid address error if attempted.
The STATICROUTEEN pin works as a global enable / disable for the static routing feature during
reset. The feature is enabled if the pin is high during reset and disabled if the pin is low during reset.
The RTR.RTRCFG.SR bit shows if the static routing feature is globally enabled or disabled.
Note that it is not possible to access the configuration port of the router from a port that has static rout-
ing enabled.
13.2.10 Spill-if-not-ready
The spill-if-not-ready feature can be enabled individually for each physical and logical address by
configuring the corresponding RTR.RTACTRL.SR bit. When enabled, an incoming packet is spilled