RELEASED
PM73123 AAL1GATOR-8
DATASHEET
PMC-2000097
ISSUE 2
8 LINK CES/DBCES AAL1 SAR
Figure 51 DBCES Receive Side Buffering
Buffer Depth in Frames
70
60
50
40
Buffer Depth in
Frames
30
20
10
0
0
5000
10000
15000
20000
25000
Time (us)
9.2.2.2.11
Counters and Sticky Bits
The RALP sets sticky bits for overrun, underrun, pointer mismatch, resume,
SRTS underrun, SRTS resume, and other conditions. As with most registers, the
sticky bits are located in the external RAM. They are set by the AAL1gator-8 and
must be cleared by the microprocessor. Sticky bits provide a history of events
that have occurred. Since these bits can be set with every cell, it is better to use
the counters for statistics gathering purposes. The AAL1gator-8 increments the
counters for incorrect SNs, incorrect SNPs, cells received, underflows, overflows,
dropped cells, misinserted cells, lost cells, pointer parity errors, and pointer
mismatches. The transfer status bits can be used to detect that a clear was
overwritten by toggling transfer bit 15 with each clear of the status bits and then
reading the value immediately thereafter. Refer to “R_ERROR_STKY Word
Format” for a description of sticky bits.
The first time that a sticky bit is set for a queue that has the corresponding
enable bit set in the RCV_STAT_EN_REG register, an entry will be made in the
RCV_STAT_FIFO containing the queue number and the sticky bit which was just
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