![](http://datasheet.mmic.net.cn/330000/PM7340_datasheet_16444385/PM7340_241.png)
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
224
Word Bits
Parameter
Description
15:8
icp_offset
ICP Cell Offset. This value is programmed by the
RIPP to allow the RDAT to determine the frame
boundary on this link, and to validate this value in
the incoming ICP cells.
7
Reserved.
6
ima_version
IMA Version supported for this link. This will factor
into IMA OAM label checking, if the label_disable
bit is not set.
0 = IMA version 1.1
1 = IMA version 1.0
5
label_disable
When set, the IMA OAM label within the incoming
ICP cells will not be used for validation of these
cells. When not set, the IMA OAM label must
match that specified by the ima_version field.
4:0
lid
Logical identifier for this link. This value is
programmed by the RIPP to allow the RDAT to
validate the incoming ICP cells.
31:10
Reserved.
1
9:0
dcb_thresh
Configured overrun threshold of the delay
compensation buffer for this link (in cells
IMA
only). This must be less than or equal to the
value specified in MAX_DCB_DEPTH in the
Global configuration register. When this threshold
is exceeded (distance between the read and write
pointers), the overrun_latch error status will be
set. This threshold is programmed by the RIPP at
link startup.
RDAT Link Context Memory
The RDAT Link Context memory contains state information for a physical link.
For TC only connections, this memory should be initialized to zero. For IMA
connections, this memory is used by the RDAT to maintain the IFSM, IESM,
OSM, and the DCB write pointer for a link. Each record is two words by 32 bits
wide, and is addressed by the physical link number.