PM7340 S/UNI-IMA-8
PRELIMINARY
INVERSE MULTIPLEXING OVER ATM
DATA SHEET
PMC-2001723
ISSUE 3
INVERSE MULTIPLEXING OVER ATM
As enabled IMA events occur, a message is placed with the RIPP_INTR FIFO.
Once a message is placed with the FIFO, another message will not be generated
until the read_event command is executed for the group. During this period of
time, additional events can accumulate and will be reported with the Read_event
command when executed. The Read_event command queries the links within the
group and provides all of the link and group information in a single data structure.
To ease the processing load, a map that shows which links are experiencing
INTR conditions is provided in page 0 of the returned status. Page 1 contains the
interrupt conditions and page 2 provides the status. The majority of the
error/interrupt processing may be performed with the information provided by the
Read_event command.
12.5.14
End-to-end Channel Communication
According to the IMA spec, end-to-end channel is a proprietary communication
channel via the corresponding field in the ICP cells. The S/UNI-IMA-8 provides
access to this facility through the following means:
• In the outgoing direction, the end-to-end channel may be updated by writing
to the TX_END_CHANNEL field in the RIPP group configuration record at any
time.
• In the incoming direction, the end-to-end channel information may be
accessed by reading the ICP cell buffer memory area.
12.6 Diagnostic features
12.6.1 ICP Cell Trace
The S/UNI-IMA-8 can be configured to forward incoming ICP cells to
microprocessor, by setting the proper bits in the RIPP Group Configuration
memory. The content of the forwarded ICP cell is stored in the ICP cell buffer
registers.
The ICP cell data exchange between RIPP and the microprocessor is controlled
via the use of a lock bit (which is located in the ICP cell forwarding Control
register) and the PM_ICP_AVL interrupt. The data exchange protocol is as
follows:
1. S/UNI-IMA-8 sees a new ICP cell and starts polling the lock bit.
2. If the lock bit is current set, the cell is not forwarded.
PROPRIETARY AND CONFIDENTIAL TO PMC-SIERRA, INC., AND FOR ITS CUSTOMERS’ INTERNAL USE
280
PMC [ PMC-SIERRA, INC ]
