
PM73487 QRT
PMC-Sierra, Inc.
PMC-980618
Issue 3
622 Mbps ATMTraffic Management Device
Released
Datasheet
53
3.2.4.5
Types of Failures and Their Manifestations
Table 6 shows possible faults, their effects, and how they affect the network.
Parity fail.
ACK sent out on
h
. Parity errored cell
dropped. TX_PARITY_FAIL (refer to
“TX_PARITY_FAIL” on page 111
) sig-
naled to the microprocessor.
ACK already sent by the time the QRT
has detected a parity error. In this case, a
cell that was dropped was ACKed.
Table 6. Faults and Effects on the Network
Fault
Manifestation
Effect on Network
Wire
Connection
Data line from SE_D_IN#(3:0) stuck at
0 or 1.
Invalid idle cell, cells with
missing Cell Present and
parity error.
Port shut down ( interrupt gener-
ated and backpressure withheld)
on receipt of first 2 consecutive
bad idle cells until condition is
fixed, as port failure is sent to the
source of data by lack of backpres-
sure indication. If only one bad
idel cell received, due to the
round-trip delay between the QRT
and the QSE, the source could
send another (user) cell, causing
the destination (QRT) to come out
of the shut down state. This means
the raw interrupt at QRT
(SE_INPUT_PORT_FAIL) will
be asserted and deasserted. The
lateched interrupt
(SE_INPUT_PORT_FAIL_LATC
H) will still be asserted.
SE_SOC_IN(3:0) line stuck at 0 or 1.
Loss-of-lock on special cod-
ing on SE_SOC_IN(3:0).
Port shut down until condition is
fixed, as port failure is sent to the
source of data by lack of backpres-
sure indication.
BP_ACK_IN(3:0) line stuck at 0 or 1.
Loss-of-lock on special cod-
ing on BP_ACK_IN(3:0).
Port shut down until condition is
fixed.
Bridging fault within a port.
Invalid idle cell with some
10/01 fail or parity error.
Port shut down on receipt of first
bad idle cell until condition is
fixed, as port failure is sent to the
source of data by lack of backpres-
sure indication.
Table 5. Failure Conditions, Switch Fabric-to-ORT Interface (Continued)
Fault Detected On g
Action Taken
Comment