A 16Byte transmission occurs

1
MBT to SLICs SCL Format
Begin Event Char.

• A 16-Byte transmission occurs
• for every L1-Period/L1-Accept
• Each field is an unsigned Byte
• Transmission ordered from
• top to bottom
• 2nd byte is transmission length
• in 16-bit words
• Upon End-of-event, SLICs
• add a 4-Byte physical trailer

The Status Byte
bit0 L1_PERIOD 1 bit1 L1_ACCEPT 1 bit2
L2_PERIOD 0 bit3 L2_ACCEPT 0 bit4
L2_REJECT 0 bit5 INIT_SECTION bit6 0
bit7 0
End Event Char.
See next page for L1_Qualifiers
2
L1 Qualifiers
http//www.pa.msu.edu/hep/d0/ftp/l2/data_transfer/
L1_Qualifiers.pdf
For now, only four of the LSBs are of relevance
to SLICs
8 7 6 5 4 3
2 1 0

• SLIC action under
• L2UnbiasedSample, and L2ForcedWrite
• is exactly the same ( F-bit )
• Unbiased Sample events all go to a special
  Monitoring stream,
• whose purpose is to run the simulator and verify
  that the trigger
• hardware is working properly. If one of those
  events occasionally
• passes normal trigger conditions, then it would
  ALSO be written
• to a physics stream.
• Forced Write events are intended for special runs
  where every
• event, whether it passes or fails L2 and L3, is
  written to a "physics
• stream, for intensive offline study, probably of
  new trigger conditions.
• L2MuNeeded is a L2mu dedicated bit for
  event-alignment only
• use, where you can bypass data processing and
  only provide headers
• and trailers.
• Monitoring (request status) signals the need to
  collect all acumulated