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PM7340 参数 Datasheet PDF下载

PM7340图片预览
型号: PM7340
PDF下载: 下载PDF文件 查看货源
内容描述: S / UNI ATM反向多路复用, 8个环节 [S/UNI INVERSE MULTIPLEXING FOR ATM, 8 LINKS]
分类和应用: ATM集成电路SONET集成电路SDH集成电路电信集成电路电信电路异步传输模式
文件页数/大小: 334 页 / 2670 K
品牌: PMC [ PMC-SIERRA, INC ]
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PM7340 S/UNI-IMA-8  
PRELIMINARY  
INVERSE MULTIPLEXING OVER ATM  
DATA SHEET  
PMC-2001723  
ISSUE 3  
INVERSE MULTIPLEXING OVER ATM  
Figure 9  
- Inverse Multiplexing  
Physical Link #0  
IMA Group  
IMA Group  
PHY  
PHY  
PHY  
PHY  
Physical Link #1  
PHY  
Single ATM Cell Stream  
from ATM Layer  
Original Cell stream  
passed to ATM Layer  
Physical Link #2  
PHY  
IMA VirtualLInk  
Tx direction cells distributed across links in round robin sequence  
Rx direction cells recombined into single ATM stream  
10.2.2 IDCC scheduler  
The IMA Data Cell Clock (IDCC) scheduler calculates the IMA Data Cell Rate  
(IDCR) for each group that is used by both the Receive and the Transmit IMA  
processors. There is one scheduler for each direction (TXIDCC and RXIDCC),  
and each scheduler can monitor the rate of up to 8 reference clocks; each  
scheduler can also generate up to 8 IDCC clocks based upon IDCR. For each  
group, the reference link can be selected to be one of the 8 monitored links. Each  
of the monitored links can only be the reference link for one group. IDCR is  
calculated using the following equation, with Non and M set independently for  
each IDCR generator. Non is the number of active links, M is the size of the IMA  
frame, and TRL Cell Rate (TRLCR) is the cell rate of the reference link.  
IDCR = Non X TRLCR X (M-1/M) X (2048/2049)  
TRLCR is generated from the byte rate. The byte rate is obtained by monitoring  
the data transfers on the internal bus in the TC layer.  
For each IDCR clock tick, a service request is generated and placed into a rate  
based FIFO. Since there may be many requests generated in a short amount of  
time and the rate at which each request is generated may be different, a method  
is required to arbitrate between the requests to prevent blocking of high rate  
PROPRIETARY AND CONFIDENTIAL TO PMC-SIERRA, INC., AND FOR ITS CUSTOMERS’ INTERNAL USE  
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