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PRELIMINARY
INVERSE MULTIPLEXING OVER ATM
PM7340 S/UNI-IMA-8
DATA SHEET
PMC-2001723
ISSUE 3
INVERSE MULTIPLEXING OVER ATM
PROPRIETARY AND CONFIDENTIAL TO PMC-SIERRA, INC., AND FOR ITS CUSTOMERS’ INTERNAL USE
222
Table 24
RDAT TC Group Statistics Record
Word
Parameter
Description
0
atm_cells
Count of the number of cells which have been
read from the DCB and transferred to the ATM
layer for this TC group.
1
dropped_cells
Count of the number of cells which have been
dropped solely due to ATM layer congestion for
this group.
RDAT Validation Memory
The RDAT Validation record contains configuration information for a physical link.
This memory is configured by the RIPP (via the IMPB interface) for IMA
operation; it is used by the cell writer to validate incoming ICP cells and to control
the flow of data to the delay compensation buffers. For a link which is to be used
for TC only mode, the single bit tc_mode bit must be programmed. All other bits
are maintained by the S/UNI-IMA-8 and should be set to zero at link
configuration. Each record is two words by 32 bits wide, and is addressed by the
physical link number.
MEM_ADDR = Physical Link Number
Table 25
RDAT Validation Record
Word Bits
Parameter
Description
0
31
tc_mode
tc_mode controls whether the link is in TC mode
or part of an IMA group
0
IMA link. Flow of cells is controlled by the
IMA protocol and the current IMA state
1
TC Enabled. Cells received for this link are
stored in a shallow FIFO in the SDRAM
and scheduled for immediate transmission
out the group FIFO.