Sep 25 – 29, 2006
Valencia, Spain
Europe/Zurich timezone

A multi-channel optical plug-in module for gigabit data reception

Sep 27, 2006, 2:15 PM
25m
Valencia, Spain

Valencia, Spain

IFIC – Instituto de Fisica Corpuscular Edificio Institutos de Investgación Apartado de Correos 22085 E-46071 València SPAIN

Speaker

Paschalis Vichoudis (CERN)

Description

A plug-in module has been built for reception of optically transmitted data by gigabit applications. The optical receiving module is based on a 12-channel optical receiver and an FPGA with embedded deserializers. It is compatible with the G-Link and Gigabit Ethernet compliant serializer ASIC (GOL) used by many LHC systems. Due to its compact design, several of these modules could be plugged into VME readout systems. This module will be the principle element for both the CMS Preshower data concentrator card and the TOTEM front-end driver. The possible use of this module for the readout of the ALICE silicon pixel detector is also under examination.

Summary

Recent studies have shown that the requirements of the
Preshower for on-line data-
reduction cannot be met by existing readout hardware
designed for use by other CMS
sub-detectors. Hence the need for the development of a
CMS Preshower data
concentrator card coincided with similar requirements with
the TOTEM experiment.
This gave birth to the idea of a modular VME readout
system, common to both systems.
This will allow selection of which constituent modules are to
be used, depending on
the requirements of each system. The idea of a modular
system is also very
attractive because it can speed up production, by sharing
development between
different labs.
The principle element of the new VME readout system is the
plug-in module used for
reception of optically transmitted data by the front-end
electronic systems. The
optical receiving module is based on a 12-channel optical
receiver and an FPGA with
embedded deserializers. The 12-channel digital optical
receiver (NGK’s POR10M12SFP)
used is the one specified for the CMS ECAL optical links. The
FPGA used (Altera’s
Stratix GX family) incorporates up to 20 embedded hardware
deserializers with data
rate up to 3.125 Gbps. The FPGA is compatible with both the
Gigabit Ethernet (8b/10b
encoding) and G-Link (CIMT encoding) protocols supported
by the GOL serializer ASIC
used in the front-end systems of both the Preshower and
TOTEM. The deserialized data
are provided by the FPGA to the parallel output bus which
can be up to 216 bits
wide. A 64-bit bidirectional bus is reserved for controlling the
module. The optical
receiving module also provides an optional connector on top,
for attaching an S-
Link64 transmitter mezzanine card, if required (i.e. for the
TOTEM front-end
driver). In addition, an optional electrical gigabit serial
output is provided for
future use. Although the total number of interconnections is
large, its size was
kept relatively small (7.5cm x 11.5cm), allowing several of
these modules to be
plugged onto a VME-9U board.
The functionality of the module has been tested with both
the CMS Preshower front-
end electronic system and the TOTEM front-end system
emulator, and its behavior been
deemed satisfactory. Some additional tests done with the
PILOT ASIC have shown that
the module could also be used for the readout of the ALICE
silicon pixel detector.
Besides forming the basis of the CMS Preshower data
concentrator card and the TOTEM
front-end driver, it is envisaged that this compact plug-in
module will also be
useful for the readout of other detector electronics systems,
for LHC and beyond.

Primary author

Co-author

Mr Serge Reynaud (CERN)

Presentation materials