A data readout module for the TOTEM experiment

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A data readout module for the TOTEM
experiment Anelli G.1, Antchev G.1, 2, Aspell
P.1, Chalmet P.3, Da Silva J.4, Kaplon J.1,
Mugnier H.3, Reynaud S.1, Saramad S.1, Snoeys
W.1, Varela J.4, Vichoudis P.1 1 CERN,
European Organization for Nuclear Research,
Geneva, Switzerland 2 INRNE, Institute for
Nuclear Research and Nuclear Energy, Sofia,
Bulgaria 3 C4I, Centre de Compétence en
Conception de Circuits Intégrés, Archamps,
France 4 LIP, Laboratório de Instrumentação e
Física Experimental de Partículas, Lisbonne,
Portugal E-mail Gueorgui.Antchev_at_cern.ch
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TOTEM Electronics System
GEM
GEM
CSC
CSC
RPS1
RPS2
RPS3
RPS4
GEM
GEM
CSC
CSC
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APV
APV
CMS DAQ System
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Digital Front-End Driver
Functional Blocks
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Digital Front-End Driver cont.
Strategy for the TOTEM FED
Requirements - Need to satisfy two different
applications CMS preshower , TOTEM - With
vastly different data density (VFAT 1
bit/detector channel per event, preshower many
bits/channel/event), therefore 3 Slinks vs.
1 - Operation in experiment within VME
environment - also standalone possible using PC
and USB Implementation - This realized with
motherboard with mezzanines - Optical
components on mezzanines - can be tested
separately and recovered in case of motherboard
failure - Big mezzanine to carry out zero
suppression/pedestal subtraction for
preshower - With other mezzanine and
reconfigure can have the emulator board This
work relies on ECAL experience with DCC
development board and CMS Preshower stand-alone
test bench
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Digital Front-End Driver cont.
Block Diagram
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VFAT Data Format
VFAT Data Format for Multiple Triggers

• Total length is 16 bits, where
• BClt110gt is Bunch Counter number
• EClt70gt Event Counter
• Flagslt30gt
• Chip IDlt110gt
• Datalt1270gt
• CRC 16 checksumlt150gt
• and four control bits for the beginning of the
  frame.

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Common CMS Data Format

• BOE_n Identifier for the beginning of an event
  fragment (BEO_1 hex 5)
• Evt_ty Event type identifier
• LV1_id The level-1 event number generated by the
  TTC system
• BX_id The bunch crossing number. Reset on every
  LHC orbit
• Source_id Unambiguously identify the data source
  (FED/DCC) 2 bits reserved for FED internal
• FOV Version identifier of the FED data format
• H when set to '0', the current header word is
  the last one. When set to '1', another header
  word is following
• EOE_n Identifier for the end of an event
  fragment (EOE_1 hex A)
• Evt_lgth The length of the event fragment
  counted in 64-bit words including header and
  trailer
• CRC Cyclic Redundancy Code of the event fragment
  including header and trailer
• Evt_stat Event fragment status information
• TTS Current values of the TTS bits
• T when set to '0', the current trailer word is
  the last one. When set to '1', another trailer
  word is following
• x Indicates a reserved bit
• Indicates a bit used by the S-LINK64 hardware.

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TOTEM Digital Front-End Driver

• - 3 x NGK Receivers for 36 channels
• - 3 x Receiver Blocks / Deserializers
• Event Builder
• Spy Memory
• 3 x S-Links on board
• 1 S-Link on the rear
• 3 x USB2.0
• TOTEM need
• 8 FED Boards
• 24 S-Link64
• 2 RP stations in 1 FED, GEM in 1 FED
• Advance Event Manager
• - Time, Delay and Resources

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TOTEM Readout/Test System
cPCI Crate
VME64x Crate
FRL
TTC
or FED Kit