LECC2004: Performance of the CMS Silicon Tracker FED: Greg Iles 13 September 200 4 1 Performance of the CMS Silicon Tracker Front- Performance of the CMS Silicon Tracker Front- End Driver End Driver 10th Workshop on Electronics for LHC Experiments 10th Workshop on Electronics for LHC Experiments and Future Experiments and Future Experiments R. Bainbridge, E. Corrin, C.Foudas, J. Fulcher, G. Hall, G. Iles , J. Leaver, M. Noy, M. Raymond, O. Zorba Imperial College D. Ballard, I. Church, J.A.Coughlan, C.P.Day, E.J.Freeman, W.J.F.Gannon, R.N.J. Halsall, M. Pearson, G. Rogers, J. Salisbury, S. Taghavi, I.R.Tomalin CCLRC Rutherford Appleton Laboratory I. Reid Brunel University Presented by Greg Iles: [email protected]
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Performance of the CMS Silicon Tracker Front-End Driver
Performance of the CMS Silicon Tracker Front-End Driver. R. Bainbridge, E. Corrin, C.Foudas, J. Fulcher, G. Hall, G. Iles , J. Leaver, M. Noy, M. Raymond, O. Zorba Imperial College - PowerPoint PPT Presentation
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LECC2004: Performance of the CMS Silicon Tracker FED: Greg Iles13 September 2004 1
Performance of the CMS Silicon Tracker Performance of the CMS Silicon Tracker Front-End Driver Front-End Driver
10th Workshop on Electronics for LHC 10th Workshop on Electronics for LHC Experiments and Future ExperimentsExperiments and Future Experiments
R. Bainbridge, E. Corrin, C.Foudas, J. Fulcher, G. Hall, G. Iles, J. Leaver, M. Noy, M. Raymond, O. Zorba
Imperial College
D. Ballard, I. Church, J.A.Coughlan, C.P.Day, E.J.Freeman, W.J.F.Gannon,R.N.J. Halsall, M. Pearson, G. Rogers, J. Salisbury, S. Taghavi, I.R.Tomalin
Opto-to-electrical conversion Digitise & sync data Find hit clusters
Time
LECC2004: Performance of the CMS Silicon Tracker FED: Greg Iles13 September 2004 5
FED statusFED status
At LECC ’03 in AmsterdamAt LECC ’03 in Amsterdam– Start ‘03: The first two FEDv1 boards were manufactured– June ‘03: After testing showed there were no major faults a further 3 FEDv1 boards were produced
Progress in the last yearProgress in the last year– Sept. ‘03: Further 6 boards had serious problems– Start ‘04: A further batch of 6 boards manufactured and assembled at
different company– Spring ‘04: FEDs distributed to CERN, Pisa, Lyon– June ‘04: Beam test at CERN– Sept. ‘04: FEDv2 should return from manufacture.– End ‘04: Manufacture a further 20 FEDv2 assuming no surprises.
Software and DAQ for the CMS Silicon Tracker Front End Driver Software and DAQ for the CMS Silicon Tracker Front End Driver Poster by Jon FulcherPoster by Jon Fulcher
The Manufacture of the CMS Tracker Front-End DriverThe Manufacture of the CMS Tracker Front-End Driver
Poster by John CoughlanPoster by John Coughlan
LECC2004: Performance of the CMS Silicon Tracker FED: Greg Iles13 September 2004 6
Quad Data Rate SRAM. Handles 640MB/s in/out simultaneously.
LECC2004: Performance of the CMS Silicon Tracker FED: Greg Iles13 September 2004 15
Buffer testsBuffer tests
Check FED buffers can handle high rates & occupanciesCheck FED buffers can handle high rates & occupancies– Want to test “unconstrained” FED
• Don’t want slink back pressure limiting results• Slink throttle disabled.• Data sent to slink oblivion
– Ideally would like all FED buffers to assert “Busy” or “Warn” when becoming full.
• If buffer overflow inevitable -> Detect the event, but ignore data• Set flag to indicate data loss and record the number of these
events
– Not possible yet, although BE buffer can assert throttle signals• Use different approach. Not perfect, but still informative.• No throttling used• Count number of triggers before FED hangs
LECC2004: Performance of the CMS Silicon Tracker FED: Greg Iles13 September 2004 16
Buffer test resultsBuffer test results
Conditions:Conditions:Data taken in Zero Suppression mode
Single strip clusters used to create largest event size possible and thus worst case.
APV frame occupancy kept constant. - e.g. 6 strips = 4.7% occupancy - Easier to understand results. - Large buffers -> Valid approx
Performed 5000 "tests“. Each comprised 100k triggers, 100kHz Poisson distributed
Results:Results:FED handles single strip occupancy up to 6.25% (8 single strip clusters)
100
101
102
103
104
105
106
Mea
n lif
etim
e [n
umber
of
trig
gers
]
1612840
Occupancy [%]
Poisson-distributedtriggers (100 kHz mean)
LECC2004: Performance of the CMS Silicon Tracker FED: Greg Iles13 September 2004 17
Deadtime Versus OccupancyDeadtime Versus Occupancy
48MB/s of debug information in zero suppressed mode in addition to 32MB/s of status information.
SlinkSlink– Limited to average
rate of 248 MB/s
CMSCMS– Maximum = 3%
occupancy, but large cluster width > 1
60
50
40
30
20
10
0
Dea
dti
me
(Tri
gger
s V
etoe
d %
)
543210
Occupancy based on single strip clusters (%)
3.53.02.52.01.51.00.5
Measured average event size minus debug inf o (kB)
Slink operating at 248MB/ s which is equivalentto 200MB/ s without FED debug information
Worst case because FED uses data f ormat, which is ineffi cient f or single strip clusters. Need more realistic "f ake" data to simulate CMS high ocupancy regions.
LECC2004: Performance of the CMS Silicon Tracker FED: Greg Iles13 September 2004 18
Cluster algorithmCluster algorithm– Following is simplification,
however:• 1 byte pos• 1 byte width• 1 byte for every hit strip
Calculate average event sizeCalculate average event size– Make some simplifications
• Ignore data padding for byte aligned data
• Ignore 2 dead channels
Beam test June 2004Beam test June 2004– Average cluster width = 1.29 strips– Average cluster event size = 3.29 bytes
100
80
60
40
20
0
Dea
dti
me
(Tri
gger
s V
etoe
d %
)
43210
Measured average event size minus debug inf o (kB)
Measured deadtime
Average event size based on 3% occupancy
Measured: single strip clusters Theory: single strip clusters Theory: beam test clusters Theory: fi xed cluster width of 2
LECC2004: Performance of the CMS Silicon Tracker FED: Greg Iles13 September 2004 19
SummarySummary
FED v1FED v1– Commissioning tests at RAL, Imperial & CERN continuing well.– Baseline firmware and software operational.
FED v2 and S-link Transition cardFED v2 and S-link Transition card– Both back from manufacture in August ’04– Only preliminary results so far, but everything seems OK
FutureFuture– System integration
• Calibration of Tracker, Databases, Large system issues (e.g. error handling)– Production issues
• Tender, Industrial testing– Continued testing
• Beam test in October, Continued testing with the Fed Tester.– Commissioning
• Start to plan
LECC2004: Performance of the CMS Silicon Tracker FED: Greg Iles13 September 2004 20
More information...More information...
Software and DAQ for the CMS Silicon Tracker Front End Driver Software and DAQ for the CMS Silicon Tracker Front End Driver Poster by Jon FulcherPoster by Jon Fulcher
The Manufacture of the CMS Tracker Front-End DriverThe Manufacture of the CMS Tracker Front-End Driver