S/UNI-IMA-4 Telecom Standard Product Data Sheet
Released
OOCDE
The OOCDE bit enables the generation of an interrupt due to a change in the cell
delineation state. When OOCDE is set to logic 1, the interrupt is enabled.
DDELIN
The indirect disable delineate enable bit (DDELIN) configures the TC processor to perform
cell delineation and header error detection on the incoming data stream. When DDELIN is
set to logic 0, the cell alignment is established and maintained on the incoming data stream.
When DDELIN is set to logic 1, the RTTC does not perform any processing on the
incoming stream, but passes data through transparently.
DDSCR
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The DDSCR bit controls the descrambling of the cell payload with the polynomial x + 1.
When DDSCR is set to logic 1, cell payload descrambling is disabled. When DDSCR is set
to logic 0, payload descrambling is enabled.
IDLEPASS
The IDLEPASS bit controls the function of the idle cell filter. When IDLEPASS is written
with a logic 0, all idle cells (i.e., the first four bytes of a cell: x00, x00, x00, and x01) are
filtered out. When IDLEPASS is logic 1, idle cells are passed to the Receive IMA Data
Processor. For IMA links, this bit must be set to a logic 1 to allow for proper IFSM
operation (the Receive IMA Data Processor will drop cells according to the configuration of
IMA_IDLE_FWD_EN and the current defects and RX LSM). For TC-only links, the
Receive IMA Data Processor will forward idle cells. If this is undesirable, then IDLEPASS
must be configured to a logic 0.
UNASSPASS
When UNASSPASS is written with a logic 0, all unassigned cells (i.e., the first four bytes of
a cell: x00, x00, x00, and x00) are filtered out. When UNASSPASS is logic 1, unassigned
cells are passed to the Receive IMA Data Processor. For IMA links, this bit must be set to a
logic 1 to allow for proper IFSM operation (unassigned cells will be forwarded by the
device). For TC-only links, the Receive IMA Data Processor will forward unassigned cells.
If this is undesirable, then UNASSPASS must be configured to a logic 0.
Proprietary and Confidential to PMC-Sierra, Inc., and for its customers’ internal use.
Document No.: PMC-2020889, Issue 2
129
PMC [ PMC-SIERRA, INC ]
