![](http://datasheet.mmic.net.cn/330000/PM7329-BI_datasheet_16444382/PM7329-BI_29.png)
PM7329 S/UNI-APEX-1K800
DATASHEET
PMC-2010141
ISSUE 2
ATM TRAFFIC MANAGER AND SWITCH
PROPRIETARY AND CONFIDENTIAL TO PMC-SIERRA, INC., AND FOR ITS CUSTOMERS’ INTERNAL USE
15
Table 2
- Sample feature set as a function of memory capacity
Context
Memory Size
SSRAM
Cell Buffer
Memory Size
SDRAM
# VC
# Cell
Buffers
Address
Mapping
Support
Shaping
Support
1 MB
4MB
1024
64 K
Yes
No
2 MB
4MB
1024
64 K
Yes
Yes
2 MB
16MB
1024
256 K
Yes
Yes
The S/UNI-APEX-1K800 provides facilities to enable sparing capability with
another S/UNI-APEX-1K800 device. The facilities enable a 'warm standby'
capability in which connection setup between the two devices can be maintained
identically but some cell loss will occur at the point of device swapping. The
facilities do not include a cell by cell lock step between the two S/UNI-APEX-
1K800 devices. To avoid any cell replication, queues in the 'spare' S/UNI-APEX-
1K800 will be kept empty, thus causing all queued traffic in the 'active' S/UNI-
APEX-1K800 to be lost at the point of switch over. However, since connection
setup is maintained identically between the two S/UNI-APEX-1K800 devices,
switch over can happen instantaneously, thus avoiding any connection timeout or
tear down issues.
The S/UNI-APEX-1K800 facilities provided are the disable and filter control bits
in the Receive and Transmit Control register. These control bits are asserted in
the spare S/UNI-APEX-1K800 to ensure the queues remain empty until
swapping is initiated. Alternatively, asserting only the filter enable bits allow
signaling and control traffic continuity to be maintained to the spare S/UNI-APEX-
1K800 to enable datapath integrity testing on the spare plane and to ensure
control communications paths to the spare plane are usable.