Protocols | CTOC | L1

Media: copper, LVDS-28 bit
Record Length: fixed, 7 frames

TS\Bit 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
1 BOR HP SC [12:7] XPT+TC XPT-TC XPT+NC XPT-NC PM GI Rec Type
2   HP SC [6:1] HPT+TC HPT-TC HPT+NC HPT-NC OL-OCT SCL FX
3   HP SC [0] MSC [8:4] MPT+TC MPT-TC MPT+NC MPT-NC 0 T1 T2 #PSC
4   HP 0 MSC [3:0] LPT+TC LPT-TC LPT+NC LPT-NC SUM of pT
5   HP Isolated Track Octant Isolated Track Octant Isolated Track Octant
6   HP Octant RA High Pt Sector 0 Isolated Track Octant Isolated Track Octant
7   Vertical Parity

Field Definitions

note: empty cells or cells marked 'reserved' will contain zeros

BOR    Beginning of record, "111"

HP     Horizontal Parity bit

*PT+*C Track counts sorted by:
       PT (X=max, H=high, M=medium, L=low)
       Curvature (+ or -)
       CPS cluster association (T=tight match, N=no match)

PM     Pass-and-Mark, not supported, "00"

SC     Singlet Count.  The total number of hit singlets in this octant
       range is 0 - 4800.  Not truncated.

MSC    This field indicates the highest sector occupancy (expressed in singlet hits)
       in the octant.  Range is 0 - 480.  Not truncated.

GI     Set if at least one isolated track in the octant is located in a
       sector with occupancy below a given value.

Rec Type L1 record, "111"

OL-OCT   Octant occupancy level, based on doublet counts.
         Note this IS truncated!

SCL      SCLinit control bit

FX       First Crossing control bit marks bunch crossing number 7

Octant   The octant number, range 0-7

Rec Type   L1 record, "111"

T1         Set if at least one isolated track in the octant is loosely
           associated with one CPS cluster.  NOTE: loose cluster matching
           is not supported so this bit is always zero.

T2         Set if at least one isolated track in the octant is loosely
           associated with two CPS clusters.  NOTE: loose cluster matching
           is not supported so this bit is always zero         

#PSC       The number of CPS clusters found in this Octant ("111" means 7 or more)

Sum of pT  The total sum of transverse momentum for all tracks found in this Octant

Isolated Track Octant = If only one track is found in this sector and no tracks
                        are found either of the adjacent sectors this byte will be
                        filled in as follows:
                        bit 7:      Set to indicate a valid isolated track byte.  If this bit is
                                    cleared ignore the rest of the byte.
                        bits [6:4]: CPS cluster association "001" = tight match, "000" = no match
                        bit 3:      Track curvature bit
                        bits[2:1]:  Track PT bin ("00" = Max, "01" = High, "10" = Medium, "11" = Low)
                        bit 0:      Set to indicate that the sector doublet occupancy is below a given
                                    threshold, currently ~6%

RA High pT Sector       The relative address (0-9) of the sector in this octant with the
                        highest sum of Pt.

VP   Vertical Parity bit


Revision History

01 Nov 2005: created JTO
03 Jan 2006: added parity links  JTO
26 May 2006: ugh... previous versions were wrong (DFEA2 L1 record) fixed now JTO
14 Nov 2006: added vertical parity, identify the fields that the CTTT actually looks at.
             removed reference to "Rel Sector" field.
19 Jan 2007: added SC and MSC sector count fields.
30 Jan 2007: added note concerning T1 and T2 fields.

jamieson@fnal.gov
Last modified: Tue Jan 30 17:16:46 2007