180 likes | 190 Views
TMB Firmware Updates. Various improvements, for example: ME1/1 fixes strip ordering and ME1/1a trigger shutoff TMB ALCT communication improvements Error-correcting code (ECC), etc. New test software/firmware Cosmic ray comparison with trigger emulation code Future enhancements
E N D
TMB Firmware Updates • Various improvements, for example: • ME1/1 fixes • strip ordering and ME1/1a trigger shutoff • TMB ALCT communication improvements • Error-correcting code (ECC), etc. • New test software/firmware • Cosmic ray comparison with trigger emulation code • Future enhancements • Note on the effect of closely-spaced L1A’s CSC DPG/Commissioning meeting hauser@physics.ucla.edu
Previous firmware updates • Summary of various firmware versions:http://cmsdoc.cern.ch/cms/MUON/cscTrigger/html/CERN/striplct.html • Previous TMB firmware was downloaded Nov. 18, 2008: • Special ME1/1 versions with strip re-ordering (next slide) • Continuous raw hits buffer for readout (no deadtime due to readout) • Counts raw hits RAM parity errors (neutron single-event upset monitor?) • 160-channel logic "scope" can read out in the DMB data stream • Option for 6:1 data compression mode for ALCT Eproms for faster downloading (not yet used) • Can read out non-LCT events (not yet used) • Added CLCT pattern ID threshold cut (not yet used) • Detects and counts TTCrx lock lost and qPLL lock lost from CCB CSC DPG/Commissioning meeting hauser@physics.ucla.edu
ME1/1 fixes – strip reordering • 4 TMB firmware versions compiled: • Type A: normal chambers (no reversed strip order) • Type B: all strip reversed (not used) • Type C: normal ME1/1B, reversed ME1/1A (+ endcap), strips unstaggered • Type D: reversed ME1/1B, normal ME1/1A (- endcap), strips unstaggered • ME1/1 firmware types were incorrectly assigned to chambers in Nov. 2008 downloads, corrected Apr. 7, 2009 • Now Emulator study shows that CLCTs are reversed (as expected) but comparator hits are not (unexpected offline) • Necessary code is available in Unpacker but not yet switched on CSC DPG/Commissioning meeting hauser@physics.ucla.edu
Current firmware update • Most recently TMB firmware was updated April 7, 2009. • Firmware version from March 16, 2009 • Features described in next slides • Needs matching ALCT firmware changes • Pretty good error detection/correction system • Eagerly anticipated and expected in a few days CSC DPG/Commissioning meeting hauser@physics.ucla.edu
ME1/1A trigger shutoff • Recall that strips are ganged 3:1 in the inner section of ME1/1 • Send LCTs from ME1/1A to Track Finder? • No? Darin’s choice at higher luminosity • (the default configuration in TMB & emulator) • Yes? Wesley’s choice at low luminosity • Easy reconfiguration - VME register bit • Implemented in Apr. 7 firmware download • N.B. readout of ME1/1A (CFEB, CLCT, ALCT information) is unaffected CSC DPG/Commissioning meeting hauser@physics.ucla.edu
TMB-ALCT communication improvements 1) ALCTTMB data path: has had CRC word at end to check data integrity for a long time • TMB checks and counts CRC errors. DDU monitors CRC errors as well. 2) Trigger (ALCTTMB) and command (TMBALCT) data paths: • Recently added 7/6-bit (trigger/command) ECC (error-correcting code) • TMB will continuously monitor data between the boards (16 bits TMBALCT, 30 bits ALCTTMB). • Detects and repairs all 1-bit transmission errors. Detects all 2-bit errors. Detects some >2-bit errors. • TMB also counts the number of 1-bit, 2-bit, and >2-bit errors in each direction. These counters should always be zero. CSC DPG/Commissioning meeting hauser@physics.ucla.edu
Setting ALCT tx and rx timing parameters • For correctly transmitting data in both directions: • Adjust tx and rx clock phases at 2 ns per tick • Recall “diamond” pattern of good settings • New loopback test: • Send pseudo-random data from TMBALCT which then sends it back on ALL relevant data lines. • Vary the timing parameters and find the “diamond” for good data transmission. • More data lines, more variety of data tested than previously. • As a result, the “good diamond” shrinks. CSC DPG/Commissioning meeting hauser@physics.ucla.edu
ALCT rx “dead zone” 3) Previously possible to have “dead zone” at a particular tx phase (see diagram below) • Different for every chamber – depends on cable lengths • Now can avoid by latching on opposite phase of rx clock (shifts internal timing by 12.5 ns) • NB 2 extra bx required for TMBALCT data - not the time-critical direction of data CSC DPG/Commissioning meeting hauser@physics.ucla.edu
More on ALCT rx “dead zone” • Transition might be <<2 ns step size, e.g. 100 ps? • Evidence: don’t see this effect on many chambers. • In which case the bad data scan may not see a problem. • But temperature variation etc. could cause data transmission errors. • N.B. time bin for data latching shifts by 1 across boundary! C=time bin 12, B=time bin 11 CSC DPG/Commissioning meeting hauser@physics.ucla.edu
Current status • Loopback and ECC demo firmware for ALCT: • Works okay at UCLA in special test firmware • Compiled for ALCT288/384/672 boards • PROM files and source code sent to Greg for testing (*** ECC still to be done) • PROM files and test firmware source code were sent to Alex Madorsky to be incorporated into standard ALCT firmware • eagerly awaited, may be ready for testing by Thursday. CSC DPG/Commissioning meeting hauser@physics.ucla.edu
Local trigger emulation results • CLCT trigger emulation looks good • Non-bx quantities: all 150,000 CLCTs agree • Bx numbers: 11/150,000 disagree (being investigated) • Correlated LCTs trigger emulation: • Most chambers at or about 100% agreement • Some chambers show problems • Probably related to ALCT-TMB data xmission problems? CSC DPG/Commissioning meeting hauser@physics.ucla.edu
Other new features (16-Mar-09 version) • Count pretriggers on each CFEB • Useful to spot a faulty CFEB right away • Count cases when bx0 from ALCT doesn’t agree with expected time of arrival at TMB(????) • Additional bunch crossing number offset • Originally just one offset for trigger time and L1A time • We realized that L1A signal can have different offset than bx0 due to different configurable delay of A/B data channels in TTC (argh – same optical fiber!) CSC DPG/Commissioning meeting hauser@physics.ucla.edu
Ready but not downloaded: • Optimize TMB I/O circuit and settings to get a fat timing window for more reliable operation: • LVDCI matches output impedance to 50 ohm transmission line for long traces from FPGA to the backplane driver chips rx_step=0123456789ABC0123456789ABC tx_step= 9 ---------CC-----------CC-- 18 good spots 4mA+Fast TMB default tx_step= A ---------CCCC---------CCCC tx_step= B C---------CCCC---------CCC tx_step= C CC---------CCCC---------CC tx_step= 0 CCC---------CCCC---------C rx_step=0123456789ABC0123456789ABC tx_step= 9 C--------CCCCC--------CCCC 25 good spots LVDCI_33 tx_step= A CC--------CCCCC--------CCC tx_step= B CCC--------CCCCC--------CC tx_step= C CCCC--------CCCCC--------C tx_step= 0 CCCC--------CCCCC--------C Old circuit and settings: New circuit and settings: CSC DPG/Commissioning meeting hauser@physics.ucla.edu
Improved TMB I/O circuit: • New circuit has more sophisticated interface between TMB and ALCT clock “domains”: Old: New: CSC DPG/Commissioning meeting hauser@physics.ucla.edu
Future plans • Some problems with sparse-mode readout (never used yet) to be fixed • Suppresses comparator data readout from CFEBs with no CLCT • Would like to have ALCT shutoff in case of really naughty ALCT boards. • Likewise DMB shutoff for naughty TMB boards. CSC DPG/Commissioning meeting hauser@physics.ucla.edu
L1A L1A L1A Event fixed delay L1A L1A L1A Event fixed delay Trigger rules and L1A-coincidence windows • Trigger rule holds off L1A until m bx after previous L1A • L1A coincidence windows is n bx wide • Example: m=3, n=3; worst case: • Example: m=3, n=7 (current CSC situation); worst case: • See that if n>m (like now) we have a problem CSC DPG/Commissioning meeting hauser@physics.ucla.edu
What happens? • Either get • Duplicate events (replication of readout data) or • Broken events (non-replication of readout data) • Which is better? • Duplicate events: • All subsystems (not just CSC) must duplicate in exactly the same way, otherwise NOT duplicates. • Must find a way to remove all duplicated events if serious about the data analysis. Note that events are not written to data files in L1A order. • Broken events: • Like two halves of a detector read out separately. Obviously intolerable for serious data analysis. • Therefore, CANNOT allow this situation to occur. +… ? ? +… ? ? CSC DPG/Commissioning meeting hauser@physics.ucla.edu
Closely spaced L1A’s and duplicate events • What to do? Options are: • Try to minimize the occurrence of multiple L1As (TY’s proposal) • Modify the trigger rules so that n≤m • Modify the coincidence rules so that n≤m • Suggest: • Option 1 for now • Argue for option 2 with n=m=7 (1% extra deadtime at 100 kHz, 0.1% at 10 kHz) ASAP and for timing-in period of LHC. • Transition to option 3 with n=m=3 when system well timed in with collisions. CSC DPG/Commissioning meeting hauser@physics.ucla.edu