![](http://datasheet.mmic.net.cn/330000/PM7341_datasheet_16444387/PM7341_372.png)
PRELIMINARY
INVERSE MULTIPLEXING OVER ATM
PM7341 S/UNI-IMA-84
DATASHEET
PMC-2000223
ISSUE 4
INVERSE MULTIPLEXING OVER ATM
PROPRIETARY AND CONFIDENTIAL TO PMC-SIERRA, INC., AND FOR ITS CUSTOMERS’ INTERNAL USE
374
If a timeout event occurs, another LASR procedure must be execute to continue
attempting to bring links to the active state.
In order to track the progress of the command interrupts may be enable the LSM
state changes for all of the links. This may result in a large number of events if
the group includes a large number of links.
12.5.8 Reporting Link Defects in the ICP cell
LIF, LODS, and LCD defects are automatically detected and reported in the ICP
cell by the S/UNI-IMA-84. Other physical layer defects such as LOS, OOF, AIS
are not detected by the S/UNI-IMA-84. To enable reporting of these defects, the
Set_rx_defect command is provided to force the contents of the RDI field in the
ICP cell.
12.5.9 Faulting/Inhibiting Links
The S/UNI-IMA-84 reports defects to the upper layer S/W and allows the upper
layer S/W declare fault conditions based upon defect information. In order to
force a link into a Fault or Failure state, the Unusable_Link command is used.
This link can operate on multiple links at a time. Once executed, the LSM of the
affected links are transitioned to the Unusable state. If inhibiting the link without
data loss is required, it is necessary to specify the cause as “inhibited”. Normally
when inhibiting a link, the link has been active for a while. If a link is inhibited
immediately after becoming active, data loss can occur. If the S/UNI-IMA-84 has
not yet received ICP cells from the link that indicates the link is active when the
link is inhibited, data loss may occur. Note that links currently experiencing
defect conditions will still experience loss of data even when inhibiting. When
links are faulted, the existing data within the DCB is still played out on the ATM
interface.
12.5.10
Change TRL
To change the TRL link, the Update_TRL command is used. The new TRL is
immediately used for scheduling the group and will be reported as the TRL in the
next ICP cell. If CTC timing is used, the stuffing is not affected. If ITC timing is
used, the reference link is changed to the new TRL. The first stuff on the new
TRL will occur on approximately the same frame as the stuff would have
occurred when it was a non-reference link. After the first stuff on the new TRL,
the new TRL will be stuffed every 2049 cells.