ATLAS Liquid Argon Calorimeter Read Out Driver Board
ATLAS Liquid Argon Calorimeter: Read Out Driver Board status and plans Imma Riu Université de Genève Rencontres de Bossey 12 July 2002 • Outline: – – – 12 July 2002 Introduction The LArgon readout architecture ROD system description Status and plans Conclusions Imma Riu ATLAS LArgon calorimeter: ROD Board status and plans
Introduction ATLAS detector • The ATLAS Liquid Argon calorimeter is divided into: – Barrel calorimeter (EMB) – Hadronic endcaps (HEC) – Electromagnetic endcaps (EMEC) – Forward calorimeter (FCAL) • In total, around 190 000 channels are to be read out. 12 July 2002 Imma Riu ATLAS LArgon calorimeter: ROD Board status and plans
EM Endcap prototype 12 July 2002 Imma Riu ATLAS LArgon calorimeter: ROD Board status and plans 3
The challenge of the electronics • Large dynamic energy range: [50 Me. V - 3 Te. V] 16 bits ! • The bunch crossing (BX) rate at LHC is 40 MHz (each 25 ns): For a signal of 600 ns, the pile-up takes up to 24 BXs. • Required relative energy resolution: ~ 10% / E: Pile-up and electronic noise should be minimized. Good calibration of the electronics response. Signal after shaping 12 July 2002 r to ape ec h et l s D na g si Different BXs Noise dependence on luminosity and peak time Imma Riu ATLAS LArgon calorimeter: ROD Board status and plans
The LArgon Read Out Architecture HEC 5 EMEC FCAL 3 6 FEB FEB ROD ROD EM Barrel 1 EMEC HEC 2 FEB FEB ROD 4 5 Front End Boards FEB FEB Read Out Driver Boards ROD FCAL 6 FEB FEB ROD Detector: Radiation environment USA 15: Radiation free DAQ 12 July 2002 Imma Riu ATLAS LArgon calorimeter: ROD Board status and plans 5
FEB and ROD boards functionality Located in the detector FEB FEB 8 Located in USA 15 room optical fiber 1. 6 Gbit/s ~100 m ROD 100 k. Hz event rate • • • Radiation tolerant board. 128 channels / FEB. Fast signal shaping (~ 50 ns). Five digitized points (12 bits) using three gains in the ratio 1/10/100. Gain selection (2 bits). LArgon needs ~1600 FEBs. 12 July 2002 Imma Riu • • • Event processing time 10 s. Computation of time, energy and shape quality flag ( 2). Use of optimal filtering algorithm. Use of Digital Signal Processors (DSP). Generation of the ‘busy’ signal. LArgon needs ~200 RODs. ATLAS LArgon calorimeter: ROD Board status and plans 6
ROD physical description • ROD system: – Input: 8 optical fibers with FEB raw data (16 bits @ 80 MHz) – Output: 4 optical fibers with ROD calculations (32 bits @ 40 MHz) – It consists of: • 9 U VME 64 x board: ROD module (14 RODs / crate at maximum) • 9 U VME 64 x board: Transition Module • ROD module: – ROD mother board (MB) • Uses G-link chips for deserializing the data from the optical fiber. • Includes TTCrx ASIC which provides Trigger-Time-Control information: LHC clock, event and bunch crossing identifiers, ATLAS trigger type. • Uses SDRAMs for storing raw data (for online histograms) • Uses programmable chips (FPGA). – 4 processing units (PU) mounted on top of the ROD mother board. • Include Digital Signal Processors (DSP) chips. • 2 DSP / PU. [1 DSP per FEB] • Use FPGA chips as well. 12 July 2002 Imma Riu ATLAS LArgon calorimeter: ROD Board status and plans Nevis Labs
Read Out Driver Board receiver Glink receiver Glink receiver 12 July 2002 Glink staging FPGA Processing Unit SDRAM Output Controller Ser staging FPGA Processing Unit Output Controller staging FPGA Processing Unit Imma Riu VME control SDRAM Ser SDRAM Output Controller ATLAS LArgon calorimeter: ROD Board status and plans Ser TTC 8
Processing Unit Input FPGA FIFO DSP Output FPGA Input FPGA 12 July 2002 Imma Riu DSP ATLAS LArgon calorimeter: ROD Board status and plans VME TTC FIFO 9
ROD at the beginning of LHC receiver Glink receiver Glink receiver 12 July 2002 Glink staging FPGA Processing Unit staging FPGA Imma Riu Output Controller SDRAM staging FPGA SDRAM VME control Output Controller Ser Processing Unit SDRAM Output Controller Ser ATLAS LArgon calorimeter: ROD Board status and plans TTC 10
Status of the ROD receiver Glink receiver Glink receiver 12 July 2002 Glink staging FPGA Processing Unit SDRAM Output Controller Ser staging FPGA Processing Unit Output Controller staging FPGA Processing Unit Imma Riu VME control SDRAM Ser SDRAM Output Controller ATLAS LArgon calorimeter: ROD Board status and plans Ser TTC 11
Processing Unit Input FPGA FIFO DSP Output FPGA Input FPGA 12 July 2002 Imma Riu DSP ATLAS LArgon calorimeter: ROD Board status and plans VME TTC FIFO 12
Delicate points bga chip • Cooling of G-link chips: – 35 ºC at maximum for 80 MHz clock frequency. – Cooling with water or air are being studied. • For money saving, ‘staging’ is implemented: – Half of the PUs will be used at the beginning of LHC. – The DSP processes 128*2 channels. • PCB routing with multiple ball-grid-array (bga) chips. • The output goes through serializer/de-serializer at 280 MHz. 12 July 2002 Imma Riu ATLAS LArgon calorimeter: ROD Board status and plans
Past experience in Geneva ROD demonstrator • • • ROD prototype Built in 2000. Board frequency: 40 MHz. 2 optical receivers as mezzanine in TM. 1 Output Slink in the Transition Module. 4 PUs: 1 DSP/PU, 64 channels/DSP. • • • To be built in 2002. Parts of the board at 80 MHz. 8 optical links integrated in the ROD. 4 Outputs Slink in the TM. 4 PUs: 2 DSP/PU, 128 channels/DSP. Need of four times less ROD modules. Annie, Daniel, Ilias, Lorenzo • Sending of data serialized LVDS at 280 • • MHz to the TM. (test in Geneva ok) Addition of the staging FPGAs. Use of ball-grid-array chips. • Used in Test Beams and for tests of PU. 12 July 2002 Imma Riu ATLAS LArgon calorimeter: ROD Board status and plans 14
ROD Demo Transition Module PU 1 PU 2 12 July 2002 Imma Riu Input Link Receiver PU 3 Input Link Receiver PU 4 Output Link Transmitter ATLAS LArgon calorimeter: ROD Board status and plans 15
Plans and milestones • Decision of the DSP chip: Done • ROD preliminary design review: September 2002 • Prototype production: Oct/Nov 2002 • Pre-series production: May 2003 • PRR (production readiness review) : Oct/Nov 2003 • Series production: January 2004 12 July 2002 Imma Riu (DSP TI 6414) ATLAS LArgon calorimeter: ROD Board status and plans (planned by Jan. 2002) (planned by April 2003)
Geneva ROD group • Manpower: – Engineers: • Daniel La Marra: engineer responsible of the ROD module • Annie Leger – Physicists: • Alain Blondel: project leader • Imma Riu: physicist responsible • Present responsibility: – To finish the ROD mass production by 2004. • Possible next steps: – Take part on the commissioning of the system. – Participate in the DAQ system for the RODs. 12 July 2002 Imma Riu ATLAS LArgon calorimeter: ROD Board status and plans
Conclusions • The ROD project is ongoing well in Geneva with the collaboration of LAPP and Nevis. • The Geneva group is getting ready for the preliminary design review in September 2002: finishing schematics and writing documentation. • The ROD mother board mass production is expected to be finished in 2004. 12 July 2002 Imma Riu ATLAS LArgon calorimeter: ROD Board status and plans
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