L1CTT BROADCASTING AND THE STT

L1CTT DOCUMENTATION

• CTT Communication Protocols and Data Encoding by Manuel Martin
  • Latest Version
  • Version 6.0 - May 27,1999 - for review
• L1CTT Block Diagrams Baseline as of May 4, 1999
• The April-99 Scheme Talk by Marvin Johnson presented at the April 99 Collaboration Meeting
• L1CTT to L2 Communication Protocols:
  • Talk by Manuel Martin at Paris Trigger Workshop
  • DØ Note 3626 by Manuel Martin

STT DESIGN CONSIDERATIONS

1. GENERAL
   1. Hal's talk on FRC Issues from the BU STT Workshop (June 11, 99) pdf
2. COVERAGE
   1. Need tracks from 9.5^o on each side of 60^o sector (total 79^o) to pick up all tracks with b < 2mm and Pt > 1.5 GeV.
      OK: April-99 scheme sends tracks within 85.5^o or 90^o to each FRC.
3. HARDWARE
   1. Each FRC whould receive L1CTT information by G-link via one VTM card - 4 fibers max.
      OK: April-99 scheme sends 1 fiber to each FRC.
   2. Active splitting of fibers from L1CTT should be avoided at STT.
      OK: In the April-99 scheme this is all taken care of at the L1CTT broadcaster boards.
4. DATA TRUNCATION
   1. Max number of L1CTT tracks used by STT is: still to be decided (32 per 60^o sector used in physics studies)
      OK?: Maximum sent by L1CTT = 46 ???
   2. STT truncation scheme at the FRC: still to be decided
      OK?: Approximately independent of L1CTT track broadcast scheme.
   3. Max acceptable time to receive all L1CTT tracks and transmit them to the STC's should be less than the time to receive and cluster all SMT information (3.2 us for the maximum expected SMT data size)
      OK: For max L1CTT tracks (46) the receive time is 1.8 us
5. DATA FORMAT
   1. Data format prefered by STT is: H-Layer hit + A-Layer Offset
      STILL OPEN: Some discussions:
      • Discussion of H-A vs. H-Pt Schemes by Ulrich Heintz
      • Discussion of H-A vs. H-Pt Schemes by John Hobbs
      • Discussion of L1CTT Data Formats by Dave Toback (Feb-99)
      • DØ Note 3626 by Manuel Martin
      PRELIM OK
      • Proposed Scheme (June 9, 99): A-Offset for Pt-Bins 1,2; Pt for Pt-Bins 3,4
        (see also Hal's BU STT Workshop Talk above)