CMS/HCAL/TriDas. Sept, 2003 HCAL TriDAS 1 Tridas Status Drew Baden University of Maryland September 2003

CMS/HCAL/TriDas. Sept, 2003 HCAL TriDAS 2 HTR Status Dual-LC O-to-E VME Deserializers Xilinx XC2V Stiffeners SLBs (6) TTC mezzanine Rev 3 – 30 boards made in March 2003 –Board production changes: New assembler, in-house X- ray, DFM review, QC Gold plated (Rev 1 was white- tin) for better QC –Changes to HTR: Change from FBGA (1.00mm) to BGA (1.27mm) Added stiffeners Moved all SLB/TPG output to front-panel daughterboards Modified Rx refclk scheme (the usual TTC/refclk clocking concerns) –Full 48 channel capability Rev 1 in 2002 was “half HTR”

CMS/HCAL/TriDas. Sept, 2003 HCAL TriDAS 3 TTC receiver - TTCumd General purpose TTC receiver board (TTCumd) –TTCrx ASIC and associated PMC connectors Will be used to receive TTC signal by HTR, DCC, and clock fanout boards No signal receivers. –Copper/fiber receivers must be on the motherboard –Signal driven through TTC connectors Tested successfully by Maryland, Princeton, BU groups Princeton Fanout Card

CMS/HCAL/TriDas. Sept, 2003 HCAL TriDAS 4 Clocks and Synchronization Clocking considerations can be divided into 2 parts: –Deserializers REFCLK: stability critical (80MHz frame rate) Stability: must have a very low jitter – 40ps pkpk spec Frequency: TI TLK2501 spec is 100ppm (8kHz) to lock – Measured ~350ppm (30kHz) needed to establish link »LHC variation expected to be few kHz – Once link is established, just needs to be stable (it’s a REFCLK!!!) Phase: relationship to LHC clock totally irrelevant –Phase critical clock for pipeline synchronization Must be in phase with LHC clock Jitter spec is less stringent –For FPGA sequential logic –For SLB transmission 80ps pkpk

CMS/HCAL/TriDas. Sept, 2003 HCAL TriDAS 5 HCAL Clock Fanout HTR clocks provided by a single 9U VME board –Chris Tully/Jeremy Mans from Princeton –Has fiber TTC input Signals fanned out over Cat6 twisted pair: –TTC stream To be used by each HTR and by DCC to decode commands & L1A –BC0 To be used by SLBs to synchronize TPGs –“40MHz” clock To be used by FPGA and SLBs to maintain pipeline – Comes from QPLL –“80MHz” clean clock To be used for deserializer REFCLK – Comes from QPLL

CMS/HCAL/TriDas. Sept, 2003 HCAL TriDAS 6 Clock Distribution HTR TTC fiber TTC CLK80 BC0 CLK40 distribution to 6 SLBs and to 2 Xilinx Brdcst, BrcstStr, L1A O/E BC0 TTC FPGA.. Test Points for RxCLK and RxBC MHz.. TTCrx to Ref_CLK of SERDES (TLK2501) CLK40 CLK80 Princeton Fanout Board TTCrx QPLL HTR Cat6E or Cat7 Cable

CMS/HCAL/TriDas. Sept, 2003 HCAL TriDAS 7 May Testbeam Setup Lack of a QPLL – we had to improvise: –Front-end used commercial Cypress PLL Beats GOL 100ps pkpk jitter spec in the lab Terry Shaw measured sufficiently small jitter on backplane –Fanout card No clean 80MHz REFCLK, so provided 2 alternatives: – 2xLHC clock from crystal oscillator – High quality clock from HP signal and pulse generators – Jumper selectable on mezzanine cards No clean 40MHz system clock – Just used 40MHz output from TTCrx chip anyway – Worked well enough »The system clock doesn’t need a low jitter spec, and Xilinx has a DLL to clean it up –Much struggling with the fiber links, synchronization issues, etc. Almost all issues

CMS/HCAL/TriDas. Sept, 2003 HCAL TriDAS 8 May 2003 Testbeam What we struggled with and learned about –Fiber links FE Tx clock critical. No QPLL so we used backup plan. Great deal of experience gained here. –TTC Had a few minor issues, discover how to best synch L1A with pipeline –DAQ Production DCC logic board –Able to operate SLINK64 after BU group discovered bug in documentation –Logic in place for inline error checking, data integrity, etc XDAQ implementation experience –Calorimeter Took useful calorimeter data! –HB, HE, HO, HF

CMS/HCAL/TriDas. Sept, 2003 HCAL TriDAS 9 May Testbeam Experience Fiber synchronization –FE With crystal oscillator on FE, virtually no troubles TTC 40MHz clock cleaned up by Cypress “roboclock” chip (Cy7B993) –Many synch errors, varied from fiber-to-fiber, hard to maintain link on all fibers over ~few hours time period –During synchronized beam running, sent reset between spills to ensure link. This seemed to work ok. Exploring using rescynch in abort gap… –Fanout card Fanout from onboard ~80MHz crystal oscillator for REFCLK Fanout TTC 40MHz clock for system clock –HTR 40MHz system clock scheme worked –Some firmware changes necessary to synchronize with L1A TLK2501 link circuitry always enabled.

CMS/HCAL/TriDas. Sept, 2003 HCAL TriDAS 10 Fiber Links (cont) Tests at Maryland using TI eval board and Stratos transmitter –Link exceedingly stable (see slides below) Current plan –Study FE → HTR link at FNAL FNAL test stand is setup, link tests underway, more to come this fall –Investigate noise characteristics of H2 environment H2 is clearly different than FNAL, Maryland (and BU) experience –Review of HTR and Fanout card Will learn what we need to do from the above Best guess –All tests in US indicate solid link, but experience in H2 disagree –Probably a linear combination of: TTC clock jitter (most likely) Some kind of new noise component (less likely – FE works with crystal oscillators) Bottom line: –We have a system that works in our labs (BER< ) but… H2 environment? Need more studies during the next 6-12 months Lack of working QPLL. Looking forward to getting correct QPLL/crytals

CMS/HCAL/TriDas. Sept, 2003 HCAL TriDAS 11 Optical Attenuation and BER “Typical setup” –VECSEL transmitter, coupled to fiber via LC connector Not locked, but fixed in place –Fiber to LC to 8-way MTP male on HTR front panel –Single fiber to LC connector for connection to STRATOS receiver Output power: –VECSEL advertised to put out 500  W (-3dBm) Terry Shaw measured 570  W for a particular VECSEL –UMD uses STRATOS LC transmitter Advertised output  W (-4 to -10dBM) Measured to be 90  W for a particular STRATOS About 6dB below what we will use in CMS Working on FE emulator now using GOL+VECSEL… Attenuations measured: –At each LC connector, 10 – 50% (0.5 to 1.5 dBm) –At MTP connector, same thing (.75dB advertised) –Fibers are about ¼ dBM per 100m FE VECSEL LC MTP (8-way) LC Stratos HTR

CMS/HCAL/TriDas. Sept, 2003 HCAL TriDAS 12 Optical Power (cont) What do we need at the receiver to maintain link? –Did a series of measurements with known attenuator –Varied attenuation, looked at: BER TTL “signal detect” (SD) signal provided by Stratos part –Found: SD signal goes away when power is below about 2  W –Measured 1.5  W but accuracy of meter is probably ±.2  W BER climbs very fast right at this shoulder NB: achieved BER< with multiple fibers in parallel with crystals Measured ~5k errors in 10sec Points with error bars are worst case BER: <1 error See next slide

CMS/HCAL/TriDas. Sept, 2003 HCAL TriDAS 13 Link Loss Observation Ran a test at 7.4  W (-21dBm), found 44 errors in 18 hours Simultaneously triggered scope on VCC to transmitter and crate Found that the scope had triggered on transmitter voltage but not crate –Voltage spike - 1-2V oscillation with ~50ns rise time –Crate was isolated through UPS These errors were due to a spike on the A/C line from equipment being power cycled, noise in building, etc. Moral: noise in the power/grounds will be our nightmare

CMS/HCAL/TriDas. Sept, 2003 HCAL TriDAS 14 Optical Attenuation (cont) Input power required to maintain link: –Measured failure for power < ~2  W (- 33dBm) Power output by VECSEL: –500  W output Divide by 2 for digital averaging Gives 250  W (-6dBm) output at source Expected Attenuations –Maximum of 8 couplings until the signal gets to the Stratos receiver on the HTR 8x( )dBm = (4 – 12)dBm –Add another ~1dBM due to fibers Total power at inputs to HTRs: –-6dBm – (4-13)dBm = -10 to -19 dBm –FNAL measured/calculated 7.3dB Operating would be -13dBm We should have at least 10dB margin –Probably more like 15dB VECSEL Operating

CMS/HCAL/TriDas. Sept, 2003 HCAL TriDAS 15 Longitudinal Separation Attenuation MTP connector ends are spring loaded into adapter Measured attenuation as a function of the separation –Separation should be ~0 if keys and adapters are working well –This should not be an issue for us (famous last words….)

CMS/HCAL/TriDas. Sept, 2003 HCAL TriDAS 16 Changes to HTR for Rev4 Moved 2 LC’s down to giver more clearance for fibers –Upper rear of card Spread out routing of differential pairs for 6 SLB and 2 FPGA system clocks Removed hot swapping circuits –Worry about noise, decided not to require HTR to be hot swappable Front-panel changes –Rotary switch, LEDs, eliminate REFCLK mux via jumper, etc Miscellaneous changes –Fixed what was found to be wrong with Rev3 board, add test points, other minor stuff

CMS/HCAL/TriDas. Sept, 2003 HCAL TriDAS 17 Project Timeline Firmware TB 03 firmware should be adequate Boards Can use current crop of Rev3 To do: Commission QPLL, global clocking. Level 1 Trigger: SLB, TPG, latency… “Vertical Slice” (~March) 2005 HB, HE, and ME plus Level 1/TPG Fiber synchronization Check in alcove…compare environments Firmware TPG firmware has to be ready. Fall 03 task. Boards Must have Rev4. How many TBD. FE Commissioning (~Feb) “Magnet” Tests (no HCAL) CMS Magnet Integration System Test Boards Will have Rev4. H2 Testbeam Fiber synchronization Check in H2…compare environments Boards Will have Rev4. How many TBD.

CMS/HCAL/TriDas. Sept, 2003 HCAL TriDAS 18 HTR Firmware

CMS/HCAL/TriDas. Sept, 2003 HCAL TriDAS 19 TPG Path Still under development –The following is already coded/simulated but not tested in HTR Things to do (not necessarily in order) –Linearize QIE data to 10 bits With.5GeV resolution gives 512 GeV max –Apply BCID filter Probably will sum over 2 buckets and assign based on high/low patter around the bucket that has the max energy –Sum or divide depending on HB, HE, or HF –Extract a muon window for the “feature bit” –Apply logic to eliminate false muons from shower leakage, etc. –Compress and send to SLB

CMS/HCAL/TriDas. Sept, 2003 HCAL TriDAS 20 TPG Path Schematic

CMS/HCAL/TriDas. Sept, 2003 HCAL TriDAS 21 TODO - TPG HTR production can begin after: –SLB/HTR connectivity check Logic analyzer card on SLB site already shows connectivity Need to plug in real SLBs to check that they can coincide –SLB/HTR/Wisconsin check Check that we can maintain link Will bring the setup from Princeton to Maryland this month and do the tests. Measure BER, etc. Data validation –We propose to build a 6U VME board with sites for the Wisconsin Vitesse receiver boards –Will fifo data and read out over VME –Use this to check data validity, try different TPG tests, etc. –Plan to have this board ready in a few months. Will use this for the early slice tests to test TPG output. FPGA Clock Input

CMS/HCAL/TriDas. Sept, 2003 HCAL TriDAS 22 TODO (cont) Firmware –Focus on L1 latency optimization Measure full latency, scheme for random TLK latency, how to meet L1 latency budget, etc. This will be the main activity from now until we go into production. –Bells and whistles for error reporting/recover Meeting next week in Princeton to finalize what we learned in 2003 More to be learned in 2004 HTR boards –Make Rev4 this fall, go into production early 04 ASAP given schedule Depends on results from above