raw data for … 105/04/2002 cat meeting witek krasny(cern) …the lar-calorimeter witek krasny...

105/04/2002 CAT meeting Witek Krasny(CERN)

Raw data for …

…the LAR-calorimeter

Witek Krasny (CERN)


The LAr ROD and ROB data

based upon:

• LAr TDR, CERN/LHCC 96-41. • The ROD Demonstrator for the LAr Calorimeter, ATL-

COM-Lar-99-011, 8 DEC 1998, last modified 30 March 2000.

• Stefan Simion; Compression of EM Calorimeter data, Note OCT. 1999

• … discussions with Stefan Simion (thanks for help in understanding various functional aspects of FEB and ROD electronics)

• discussion with Jorgen Beck Hansen and Luc Poggioli


The LAr ROD input data

• ~185 000 read out channels

• each channel provides 16 x Nsamples bits (Nsamples

= 3-32) for each L1 accepted trigger:

4 bits/channel - control and gain

12 bits/channel for ADC conversions

8 bits/ADC for switch capacitor addresses

• “New” mapping: 1 DSP/FEB, 8 channels/ADC, 128 channels/DSP, 256 channels/S-Link, 1024 channels/ROD, (4 S-Links/ROD)

• “Old” mapping: 2 DSP/FEB, 64 channels/DSP, 256 channels/ROD


The LAr ROB input data

Open questions:Open questions:

• Number of samples 5 …(up to 32 in special runs)

• L1A dependent transfer (not considered so far)

• Energies - zero suppression schemes (noise cuts), isolated cell treatment

• Different packing of small and large energies (16 and 32 bits)

• (time and = zero suppression schemes, treatment of out of time and badcells, etc…

• Packing of RADD words (addresses of switch-capacitors)• Intelligent compression schemes (e.g. Stefan Simion)



12+4 bits - ADC + Gain info for each channel and each sample (N_samples=5,32)

(8 bits - SCA info for each ADC (8 channels) and each sample (N_samples=5,32))

Version 0 Version 0 (N_samples)(N_samples) – “Transparent” – “Transparent”

(ROD input = ROB input)



32 bits - energy for each channel

16 bits - time for each channel

16 bits - – quality factor for each channel

Version 1Version 1 – “Preprocessed” – “Preprocessed”

Standard LAr proposal



32 bits - Best estimator of energy deposited in the L1 trigger bunch crossing for each channel

?Version2?Version2- “Reconstructed ROD info”?- “Reconstructed ROD info”? Radical user-friendly proposal


“Zero” suppression schemes

• Scheme 0: full info for all channels recorded

• Scheme 1: suppression of the and timeinfo for channels with energies below n *noise level (n=1,2,3…)

• Scheme 2?: suppression of all info for channels with energies below n *noise level (n=1,2,3…)

• NOTE: For schemes 1-2 addresses of channels with suppressed info have to be provided


“Zero” suppression schemes

• Scheme 3?: “Scheme 3” + further suppression of the and timeinfo for channels defined as “out of L1_time” defined on the basis of the and timevalues

• Scheme 4?: “Scheme 1” + suppression of info for all cells outside topologically defined Regions of Retention (R0R) (according to e.g. J.L. Pinfold scheme – Note: need to run cell clustering algorithm – most likely excluded at the ROD DSP level )

• NOTE: For schemes 3-4 addresses of channels with suppressed info have to be provided


Compression methods

• Method 0: S. Simion - “no loss of info” method which can be used for Version 0 of the ROB input data

(for the first sample the ADC count is given, for the following samples only the compressed differences are provided using the “k-bit split-sample technique of NASA szip algorithm)

• Method 1: reduction to 16 bits the info on cell energies below certain energy threshold E_hthr

• Method 2?: reduction to 16 bits the info on cell energies and reduction to 8 bits the and timeinfo below certain energy threshold E_hthr


Addressing modes for non-suppressed

channels • Mode 0: Ordering of channels according to ROD number,

S-link number (4/ROB), DSP/FEB number, ADC number,(Sample number)

(addresses of a channels specified by their position on the list)

• Mode 1?: “Nick Ellis scheme” …as for TRT for each zero-non-suppressed channel write a n-bit address offset (in

the case of more than 2**n -2 consecutive zero-suppressed channels write full address code after each group of 2**n -1 consecutive empty straws)

• Mode 2?: “Header bits” for each FEB/DSP block containing 128 channels write 4 x 32 bits – 0 for

zero suppressed channels and 1 for zero unsuppressed channels, 4 x 32 bits to identify channels with the and time info suppressed, 4 x 32 bits to identify channels with energy compressed to 16 bits and and time compressed to 8 bits each.


Example of a “Mode 2” FEB block

structure

0/1 For cells with suppressed/non-suppressed 0/1 For cells with suppressed/non-suppressed andand time infoinfo

0/1 no compression/16bit energy, 8 bit 0/1 no compression/16bit energy, 8 bit andand time compressed cells compressed cells

xx0/1 For suppressed/non-suppressed cells

Cell n emptyCell n empty

Cell m with 4 byte energy Cell m with 4 byte energy

Cell m with 2 x 2 byte Cell m with 2 x 2 byte andand time

Cell k with 2 byte long energy and 1 x 1 byte long Cell k with 2 byte long energy and 1 x 1 byte long andand time

32 bit words32 bit words

xxxx


Propositions: ROB data

Name VERSION /SCHEME/ METHOD/ MODEVERSION /SCHEME/ METHOD/ MODE Satisfying

1.Raw 0 0 0 0 1b,2b,3a,4ab,5b,6b,7b

2.Standard 1 1 1 2 1ba,2a,3ab,4a,5b,6ab,7ba

3.Inclusive 1 3 2 2 1a,2a,3b,4a,5ba,6a,7a+b

4.Radical 2 2 2 1 1a,2a,3b,4a,5a,6a,7a+b


Interface ROB-data – Reconstruction (proposition)

ROB data reconstructed ROB digits

Sub-detector domain

Raw

Standard

Inclusive

Radical

Unpacking Unpacking

Standard

Inclusive

Radical

Raw

Off-line Off-line cell and cell and cluster cluster energiesenergies

Calibration, noisy channels,etcCalibration, noisy channels,etc+ geometry mapping+ geometry mapping

Ordered Ordered according to according to Electronic Electronic channelchannel


Interface ROB-data – LV2 (proposition)

ROB data LV2 ROB data

Sub-detector domain

Raw

Standard

Inclusive

Radical

LV2 cell energies:iROD, iFEB, iADC,, iFT,

jLAY,jETA, jPHIEnergy

iXXX - electronic channel ID jXXX - geometrical channel ID

Energy – energy depositedin the L1 trigger bunch

crossing

Sub-detectorSub-detectorcontribution contribution to HLT to HLT algorithmsalgorithms

LV2 algorithms

Unpacking andUnpacking andhardware-geometryhardware-geometrymapping, rough mapping, rough calibrationcalibration

LV2 cluster energies:ETA_C, PHI_C, E_C EST1,EST2,EST3

ETA-C, PHI_C – Position of the Cluster Center of Gravity

E_C – energy of the ClusterESTx – Cluster property estimators

BackgroundBackgroundfiltersfilters

PhysicsPhysicsselectorsselectors


Interface 1: Simulation –Reconstruction-LV2

(proposition) LV2-ROB format

Raw

Standard

Inclusive

LV2 Cell energiesLV2 Cell energies

ReconstructionReconstruction domaindomain

Simulation domain

Detailed simulation:

Including:Full simulation of the Lar Front-end electronics, Including pile-up from Consecutive bunch crossings. .

EXPERT INTERFACEEXPERT INTERFACE

Standard

Inclusive

Raw

Sym-bits Rec-digits/ROB

Calibration,Dead channels,Etc.

Cell energies,time, ????????

Reconstruction format

LV2 Cluster energiesLV2 Cluster energies


Interface 2:Simulation-Reconstruction–

LV2(proposition)

Radical

LV2 - Cell energiesLV2 - Cell energies

Off-line Reconstruction Off-line Reconstruction and LV2and LV2 use use The same data structure -The same data structure -convergenceconvergence

Simulation domain

Fast simulation:

Including:Fast simulation + parameterizedresponse of deposited Cell energies.

GENERIC USER INTERFACEGENERIC USER INTERFACE

LV2 – Cluster energiesLV2 – Cluster energies

raw data for … 105/04/2002 cat meeting witek krasny(cern) …the lar-calorimeter witek krasny...

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