IDT CPS-1848 User Manual page 55

2. RapidIO Ports > Packet Trace and Filtering
2.9.1.3 Trace Routing Features
Each S-RIO port supports two operation modes for the trace routing function:
• Default Trace Routing –
• Optional Trace Routing –
2.9.1.3.1 Default Trace Routing Mode
In default mode, the trace enabled S-RIO port accepts RapidIO traffic (referenced by the received packet's destID field) as well
as traffic that matches the trace criteria of all ports. Trace-triggered packets are handled by the trace-enabled output port in the
same way as it handles all other packets. Normal RapidIO priority and flow control rules apply.
2.9.1.3.2 Optional Trace Routing Mode
In optional mode, only packets that have matched a port's trace criteria are routed to the trace port. A received packet that
does not match the
trace port. If this packet has a destID that references a multicast operation that includes the trace port, the packet is forwarded
to all ports except for the trace enabled port. A packet that does not match a port's trace criteria whose destID only references
the trace port is handled as an error packet and is dropped. Trace-triggered packets are handled by the trace-enabled output
port in the same way as it handles all other packets. Normal RapidIO priority and flow control rules apply.
A user can configure the trace port into "trace only" mode, and at the same time configure the port's route table to allow
packets to be routed to the trace port (including packets that do not match the trace criteria). With this configuration, packets
received by a port that are to be routed to the trace port (as defined by that port's route table) will be dropped by the device if
they do not match the trace criteria. Packets in this scenario that match the trace criteria are forwarded.
2.9.1.3.3 Maintenance Packets with Enabled Trace Ports
Type 8 packets are handled in the same way as all other packets for both Trace Routing Modes defined above. Type 8 packets
that are received at a trace-enabled input port that have a hop count of 0 are forwarded to the trace port if the trace criteria at
that port is met.
For Revision C, a Maintenance packet with a hop count greater than 0 is forwarded to the destination
port(s) with its hop count decremented by 1. The same packet (with its hop count decremented by 1) is
also forwarded to a trace port if trace criteria is matched.
For Revision A/B, a Maintenance packet with a hop count greater than 0 is forwarded to a trace port if
trace criteria is matched, however, its hop count remains unchanged. The same packet (with its hop
count now decremented by 1) is forwarded to the destination port(s).
2.9.1.3.4 No Route Conditions
Packets that meet the trace criteria are routed to the trace port even if the packet destID reference in the port's route table
indicates "no route".
2.9.1.3.5 Trace Function Dynamic Programmability
By offering dynamic programmability, each S-RIO port can modify trace function parameters without disabling the normal
operation of the port functionality. The dynamic programmability of the trace function allows the user to do the following
additional tasks:
• To enable/disable the trace function on an input port by input port basis
• To assign the trace function to any single output port
• To change the packet trace comparison values of any port. Note that the packet trace function at the port must be disabled
to make this change
• To enable/disable any/all trace comparison values of any port
CPS-1848 User Manual
Formal Status
Integrated Device Technology
Device Control 1 Register.TRACE_OUTPUT_PORT_MODE = 0
Device Control 1 Register.TRACE_OUTPUT_PORT_MODE = 1
Trace Criteria, but whose destID field references the trace enabled output port will not be forwarded to the
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This document is confidential and is subject to an NDA.
June 2, 2014