RELEASED
PM73123 AAL1GATOR-8
DATASHEET
PMC-2000097
ISSUE 2
8 LINK CES/DBCES AAL1 SAR
enabled.
Note that if lost cells are detected, but the queue is currently in underrun and
BITI_UNDERRUN is not set, then lost cells will not be inserted and a normal
underrun recovery will be executed. If lost cells are detected, the queue is in
underrun, and BITI_UNDERRUN is set, and less then six cells were lost, then
lost cell will be inserted and processing will occur as if the underrun did not
happen.
4. If the received SN is valid and the SN has a value equal to SN + 2 with
respect to the last SN received in sequence, then the cell is accepted and the
RALP returns to the SYNC state.
5. And finally, if the SN is valid but does not meet any of the previous criteria,
then the cell is dropped and the RALP enters the OUT_OF_SYNC state.
See Figure 34 on page 110 for the flow of the “Fast SN Algorithm”.
Anytime a cell is dropped, the R_DROPPED_CELLS , in the receive queue table
memory register,is incremented and the SN_CELL_DROP sticky bit is set.
Anytime a cell is detected lost, the R_LOST_CELLS is incremented by the
number of lost cells. Anytime the SN state machine transitions from the SYNC
state to the OUT_OF_SEQUENCE state, the R_SEQUENCE_ERR counter is
incremented. Anytime a misinserted cell is detected the R_MISINSERTED
counter is incremented. In all these cases the RCVN_STAT_FIFO will be written
with the error that occurred and the queue number for which the error occurred, if
the corresponding mask bit is not set or this is not the first unmasked sticky bit to
be set for this queue since the sticky bit register was last cleared.
PMC-SIERRA, INC. PROPRIETARY AND CONFIDENTIAL
109
PMC [ PMC-SIERRA, INC ]
