PM7312 pmc-sierra, PM7312 Datasheet - Page 246

• Manufacturer Part Number: PM7312
• Description: Freedm 32a1024l Assp Telecom Standard Datasheet
• Manufacturer: pmc-sierra

Proprietary and Confidential to PMC-Sierra, Inc., and for its customers’ internal use.
Document No.: PMC-2021833, Issue 2
CC_CNT_INTVL is set to zero. It is recommended that the counters be read at regular intervals
and, each time after they are read, that CC_CNT_INTVL be toggled to initiate a new counting
interval.
The CNT_INTVL_FLAG bit in the Connection Context Memory record is used to detect changes
of the CC_CNT_INTVL bit and to reset the counters accordingly. Each time an incoming datagram
is processed, and its Connection Context Memory record read, the value of CNT_INTVL_FLAG is
compared with CC_CNT_INTVL. If the bits are different, it is assumed that CC_CNT_INTVL has
been toggled and the counts are therefore reset. CNT_INTVL_ FLAG is inverted when the counts
are reset, so that it is equal to CC_CNT_INTVL after each datagram is processed.
Note that a Connection Context Memory record is only read when an incoming datagram
corresponding to the connection in question is being processed. It is possible, therefore, that during
a particular counting interval, no datagram is received on a particular connection. Should this
occur, that connection’s Context Memory record will not be read and the counts will not be zeroed,
even though the CC_CNT_INTVL bit was toggled by the user. Such a situation can be detected by
checking whether or not CNT_INTVL_FLAG has toggled since it was last read.
The following procedure can be used to determine a correct count value even if a counter is not
reset properly due to no datagrams being received on a particular connection during a count
interval:
Note that these counters only give an approximate count of the number of LSNE, USNE and DE bit
set events, since there is window between the count values being read and the CC_CNT_INTVL bit
being toggled, during which count events may be missed.
At the end of each count interval:
FOR each active connection {
} # end FOR
Toggle CC_CNT_INTVL to initiate new counting interval.
Read Connection Context Memory record
Extract the LSNE_CNT, USNE_CNT, DE_CNT and CNT_INTVL_FLAG fields
IF {all 3 counters = value read last time AND
ELSE IF (any counter <> value read last time AND
ELSE
END IF
# No datagram was received during poll interval.
Ignore counter values.
Correct counter values = all zeros.
# Datagrams were received during poll interval, but CNT_INTVL_FLAG
# did not invert.
# preceding poll interval.
# (or any even number of times) since a datagram was last received
# on this connection so it looked like it hadn’t toggled.
# counters therefore did not zero.
Correct counter values = values just read minus values read
last time.
# Counters zeroed properly.
Correct counter values = values just read.
CNT_INTVL_FLAG = value read last time} THEN
CNT_INTVL_FLAG = value read last time} THEN
This happens when no datagram is received in the
FREEDM 32A1024L ASSP Telecom Standard Product Data Sheet
The user toggled CC_CNT_INTVL twice
The
Released
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