![](http://datasheet.mmic.net.cn/330000/PM7341_datasheet_16444387/PM7341_24.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
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IMA Features
IMA 1.1 protocol including group and link state machines implemented by on-
chip hardware.
All ICP cell processing is performed internally by the S/UNI-IMA device with
no requirement for microprocessor intervention; however, ICP cells are made
available for diagnostic purposes.
Supports up to 42 simultaneous IMA groups.
Each IMA group can support 1 to 32 links chosen from any of the supported
links.
Each link can be programmed for either IMA processing or cell delineation.
Supports all IMA Group Symmetry modes:
Symmetrical configuration with symmetrical operation
Symmetrical configuration with asymmetrical operation.
Asymmetrical configuration with asymmetrical operation.
Performs IMA differential delay calculation and synchronization.
Provides programmable limit on allowable differential delay and minimum
number of links per group.
Supports up to 279 ms (for T1 links) and 226 ms (for E1 links) link-differential
delay among links in an IMA group.
Performs ICP and stuff-cell insertion and removal.
Supports both Common Transmit Clock (CTC) and Independent Transmit
Clock (ITC) transmit ICP stuffing modes.
Supports IMA frame lengths (M) equal to 32, 64, 128, or 256.
Optionally supports the IMA 1.0 method of reporting Rx cell information as
defined in appendix C.8 of the ATM Forum Inverse Multiplexing for ATM
Specification Version 1.1 for symmetrical configurations with M=128.