
PMC-Sierra, Inc.
PM73488 QSE
L
PMC-980616
Issue 3
5 Gbit/s ATMSwitch Fabric Element
Released
Datasheet
16
1
HOW THE QSE FITS INTO YOUR SYSTEM
The QSE, together with the QRT, supports a wide range of high-performance ATM switching systems. These sys-
tems range in size from 5 Gbps to 160 Gbps. The systems can be developed to provide scalability with linear cost.
Another key feature of the QSE/QRT architecture is that it is exceptionally fault-tolerant, both in the switch fabric
and the UTOPIA interface.
This section contains a quick overview of the QSE and several example applications:
a 5 Gbps switch using PM73487s and a PM73488,
a 10 Gbps switch using PM73487s and PM73488s,
a switch architecture using PM73487s and PM73488s that scales from 5 Gbps to 20 Gbps,
a switch architecture using PM73487s and PM73488s that scales from 5 Gpbs to 160 Gbps
1.1
The QSE is switch element, combinations of which allows switch fabric implementations that span from 5 Gbps to
160 Gbps. The bandwidth of a single QSE is 5Gbps of
sustainable
bandwidth; the raw, or peak, bandwidth is 8Gbps.
(Thus the QSE has an in-built speed-up factor of 8/5 = 1.6.)
The QSE has 32 input ports and 32 output ports. Each port is a 66 MHz 6-bit interface, out of which 4 are data and 2
are control. Each port can be connected to another QSE or QRT. Figure 2 shows a QSE connected to a QRT.
QSE System Overview
Figure 2. QSE System Overview
Physical and/or
Adaptation Layers
QRT
(PM73487)
QSE
(PM73488)
Input Cell
SDRAM
Output Cell
SDRAM
Multicast
SRAM
Receive Feedback
Receive Nibble Data
Transmit Nibble Data
Transmit Feedback
Receive UTOPIA Level 2
Interface
Transmit UTOPIA Level 2
Interface
Control
SSRAM