
ABM-3G
PXF 4333 V1.1
Functional Description
Data Sheet
56
2001-12-17
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-3G device. One ABM-3G core is used for each direction as
shown in
Figure 3-10
.
Figure 3-10
ABM-3G in Bi-directional Mode
The ABM-3G assumes that all connections are set up bi-directionally with the same Lo-
cal 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-3G 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-3G
cores are selected from the multiplexer options shown in
Figure 3-11
. Each cell is
forwarded to both ABM-3G cores and the LCI table entry for the connection determines
which of the two cores accepts the cell. The other core ignores it. Thus, each cell is
stored and queued in one of the two cores. The cell streams of both cores are
multiplexed together at the output. In normal operation, the schedulers are programmed
such that the sum of all output rates does not exceed the maximum rate supported by
ABM-3G Core
upstream
ABM-3G Core
downstream
UTOPIA
upstream
transmit
SLAVE
UTOPIA
downstr.
receive
SLAVE
JTAG interface
μ
P interface
SDRAM interface
SDRAM interface
SSRAM interface
UTOPIA
upstream
receive
MASTER
UTOPIA
downstr.
transmit
MASTER
Common
LCI Table