S/UNI-IMA-4 Telecom Standard Product Data Sheet
Released
13.5 IMA Operations
IMA operations are controlled via commands issued to the RIPP (Receive IMA protocol
processor). In general, once started, the RIPP performs the hand shaking of state transitions
between the near-end and far-end of an IMA connection.
13.5.1 Issuing a RIPP Command
The RIPP commands control the LSM and GSM state machines. The group is identified by the
group tag and the links involved are identified with a 32-bit vector. The TX_LINK_VEC has
one bit for each TX LID and bit 0 indicates TX LID 0 and bit 31 indicates TX LID31.
For symmetrical operations, the RX LIDs are not known until the ICP cells from a link are
validated. The user controls the relationship between physical links and the RX Link vector
through the RX Physical Link Table in the RIPP Group Configuration record. The RX physical
Link Table should be configured according to the TX LID values. For example, the physical
link ID for the Link with TX LID = 0 should be programmed as the RX physical link 0. When
using the RIPP commands, the physical link entered for RX physical link 0 will be controlled by
bit 0 of the RX_LINK_VEC and the physical link entered for RX Physical link 31 in the table
will be controlled by bit 31 of the RX_LINK_VEC.
For asymmetric operations, since there is not a TX link for each possible RX link and the RX
LIDs are not known until the ICP cells from a link are validated, the user controls the
relationship between physical links and the RX Link vector through the RX Physical Link Table
in the RIPP Group Configuration record. There are no restrictions on how this table should be
configured in asymmetrical mode. The contents of the RX_PHY_TABLE do not depend on
LID values. When using the RIPP commands, the physical link entered for RX physical link 0
will be controlled by bit 0 of the RX_LINK_VEC and the physical link entered for RX Physical
link 31 in the table will be controlled by bit 31 of the RX_LINK_VEC.
The RIPP command procedure is as follows:
Wait until the “CMD_BUSY” bit in the RIPP Command Register is clear.
Once the CMD_BUSY bit is clear, write the necessary data for the command registers 0x222 -
0x22C (RIPP CMD_WR_DATA1 through RIPP CMD WR_DATA3).
Write the RIPP CMD Register with the command code and group tag for the command.
Poll the “CMD_BUSY” bit in the RIPP Command Register and when cleared, check the status
of the command. Commands may be rejected when illegal actions are requested. An example
of an illegal action is to start a LASR when one is already in progress.
If the command was a “Read_event” or “Read Delay”, the returned data can now be read from
the RIPP Command Data Register Array located at addresses 0x240 – 0x2BE.
Proprietary and Confidential to PMC-Sierra, Inc., and for its customers’ internal use.
Document No.: PMC-2020889, Issue 2
278
PMC [ PMC-SIERRA, INC ]
