2. RapidIO Ports > Packet Generation and Capture
CPS-1848 User Manual
57
June 2, 2014
Formal Status
This document is confidential and is subject to an NDA.
Integrated Device Technology
2.9.1.3.9
Trace Configuration
The Trace function is enabled globally at the device level for all S-RIO ports by setting TRACE_EN to 1 in the
. When broadcast trace is enabled the Trace Output Port (TRACE_OUT_PORT) defined in the
is enabled. This register also controls the mode of the Trace Output Port (TRACE_OUT_PORT_MODE), as default or
trace only.
Each S-RIO port supports an enable of each of its four trace criteria values, TRACE_n_EN, in its respective
. This is independent such that a match on any specific value does not depend on a match of any other
value. The
Port {0..17} Operations Register
also controls whether or not a packet that matches a port’s trace criteria will cause
the device to generate a port-write packet.
2.9.1.3.10 Cut-Through Forward with Trace
Each S-RIO port supports Cut-Through forwarding when Trace is enabled if configured to do so.
2.9.2
Packet Filtering
Along with the ability to trace packets using comparisons against up to four comparison values, each S-RIO port can filter
packets based on comparisons against these same values. If this packet filtering is enabled, a successful comparison of the
first 160 bits in a received packet to a port’s pre-programmed values will cause the device to drop or “filter” the packet. A
successful comparison also prevents an S-RIO port from “accepting/processing” a maintenance packet (if a maintenance
packet that met the filter criteria had a hop count of 0).
Each S-RIO port can filter packets to be enabled/disabled for each unique comparison value at that port.
Each S-RIO port can enable/disable packet trace and packet filtering simultaneously for each unique comparison value. If both
packet filtering and packet trace are enabled and a match occurs between a received packet and a comparison value, then the
packet will be dropped but will also be traced to the specified trace port. If packet filtering is enabled but trace is not, then the
packet is filtered and not traced to the specified trace port.
The device provides a counter at each port for each comparison value which provides a continuous count of the number of
packets that were filtered at each port as a result of a successful match against each comparison value.
2.10 Packet Generation and Capture
The CPS-1848 supports a special test mode called Packet Generation and Capture (PGC) that enables initial system debug
and integration. PGC mode allows users to generate one or more packets, route those packets through the switch to a
connected device, and to capture up to 25 response packets received for that request. This mode can issue maintenance read
and write packets to verify connectivity to other endpoints and switches in a system before software is available. It can also test
a system’s reaction to incorrectly formed request or response packets.
PGC mode is normally controlled using debug tools connected directly to the CPS-1848’s I2C or JTAG interfaces when no
other control entity exists in the system. It is also possible to use PGC mode during the normal operation of a system.
Packets that are retried or stomped may still match the trace and/or filter criteria. The associated trace
and filter counters will increment for retried or stomped packets. To limit this impact, use
transmitter-controlled flow control (see
Transmitter- and Receiver-Controlled Flow Control
PGC mode requires the resources of two RapidIO ports on the device. These ports cannot be used for
any other purpose when PGC mode is active.
