PXF4336 Datasheet, PDF (60/425 Pages) Infineon Technologies AG – ABM Premium ATM Buf fer Manager

ABM-P
PXF 4336 V1.1
Functional Description
3.3
System Integration
The ABM-P has two operational modes: Bi-directional mode and Uni-directional mode.
The directional terminology for the modes refers to the usage of the ABM-P cores, not to
the connections. The connections are bi-directional in all cases. In Bi-directional mode,
one ABM-P core is used exclusively for the cells of a connection in the upstream
direction and the other core exclusively handles cells of the same connection in the
downstream direction. In Uni-directional mode, only one core always will be used to
handle the cells of a connection both in up- and downstream direction. The two basic
applications for these modes are the switch port line card application and the mini-
switch, respectively.
On a typical switch port line card, both the upstream and downstream cell flow pass
through the same ABM-P device. One ABM-P core is used for each direction as shown
in Figure 3-10.
•
SSRAM interface
SDRAM interface
UTOPIA
upstream
receive
MASTER
ABM-P Core
upstream
UTOPIA
upstream
transmit
SLAVE
Common
LCI Table
UTOPIA
downstr.
transmit
MASTER
µP interface
ABM-P Core
downstream
SDRAM interface
UTOPIA
downstr.
receive
SLAVE
JTAG interface
Figure 3-10 ABM-P in Bi-directional Mode
The ABM-P assumes that all connections are set up bi-directionally with the same Local
Connection Identifier (LCI) in both directions. In the Infineon ATM chip set environment,
the LCI is provided by the PXB 4350 E ALP and contains VPI, VCI, and PHY information.
If the ABM-P is not used with the ALP, it can extract the LCI from VPI or VCI fields or
generate the LCI by using the internal Address Reduction Circuit (ARC).
In a mini-switch application, the total throughput at 51.84 MHz is 687 Mbit/s. Only the
UTOPIA Receive and Transmit interfaces at the PHY-side are active. Both ABM-P cores
are selected from the multiplexer options shown in Figure 3-11. Each cell is forwarded
to both ABM-P cores and the LCI table entry for the connection determines which of the
Data Sheet
60
2001-12-17