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CMS ECAL. DAQ Fiber data block format Magnus Hansen 20020226. Protocol Considerations. CMS ECAL FrontEnd is sending one Trigger Tower on one 800Mb optical link to the counting room CIMT protocol is proposed as opposed to 8/10 8/10 more “standard” CIMT considered to be more robust
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CMS ECAL DAQ Fiber data block format Magnus Hansen 20020226
Protocol Considerations • CMS ECAL FrontEnd is sending one Trigger Tower on one 800Mb optical link to the counting room • CIMT protocol is proposed • as opposed to 8/10 • 8/10 more “standard” • CIMT considered to be more robust • GOL used as serialiser • Agilent Technologies G-Link 1034 used as de-serialiser • Some link data format needed Magnus Hansen, CERN-EP/CME
Features • CIMT protocol • Proprietary protocol • Agilent • IEEE standard... • Data word • 16 data bits • Flag bit • Control word • 14 data bits • Idle word • Fill frames • 8-10 protocol • Standard protocol • Data word • 8 data bits • 16 bits sent as two consecutive words • Idle word • Fill frames • Commas etc. Magnus Hansen, CERN-EP/CME
Local BCID Control word “01” 12 bits Local EVID Control word “10” 12 bits Global triggers Laser triggers Monitoring triggers Channel ID Control word “00” 3 bit channel (1-5) 3 bit strip (1-5) 7 bits tower (1-68) parity? Sample Data word 12 bit ADC data 2 bit FPPA gain 1 bit monitoring flag 1 bit forced gain flag Parity (flag bit) Checksum Control word “11” Vertical XOR Other Idle word Fill frame CIMT Data link formatword definition Magnus Hansen, CERN-EP/CME
CIMT DAQ link data block format • CIMT protocol • One tower event • BCID • EVID • 1 tower sum • 25 channels • 1 channel header • 10 samples / channel • Checksum • N.o. clock cycles • 4 + (10 + 1) * 25 = 279 cp • 6.975 us Magnus Hansen, CERN-EP/CME
Idle word Fill frame Local BCID Control word “01” 12 bits BCID 2 bits “01” Forced gain flag Local EVID Control word “10” 12 bits EVID Global triggers Laser triggers Monitoring triggers 2 bits “10” Forced gain bit Channel ID Control word “00” 3 bit channel (1-5) 3 bit strip (1-5) 7 bits tower (1-68) parity? Sample Data word 12 bit ADC data 2 bit FPPA gain 1 bit monitoring flag Checksum Control word “11” Vertical XOR Other 8-10 Data link formatword definition Magnus Hansen, CERN-EP/CME
DAQ link data block format • 8-10 protocol • One tower event • BCID • EVID • 1 tower sum • 25 channels • 1 channel header • 10 samples / channel • Checksum • N.o. clock cycles • 4 + (10 + 1) * 25 = 279 cp • 6.975 us • No Parity Magnus Hansen, CERN-EP/CME