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From: Jorgen.Christiansen@cern.ch
Date: 7/12/99
Time: 4:07:17 PM
Remote Name: 137.138.115.156
Remote User:
Dear electronic designers in LHCb We are getting closer to the point where many important features and parameters of the front-end electronics of LHCb needs to be fixed to insure a system where the different parts can work together as a reliable system. This requires quite some communication and coordination between the different implementations. This will be done using a combination of LHCb week front-end meetings , front-end workshops, LHCb notes, and the front-end electronics web pages. Front-end meetings and workshops are appropriate for discussions about different options, features, etc. LHCb notes can be used to give more details of ideas or specific implementations. The front-end electronics web pages will (should) have the latest information needed by the whole front-end community. It is also the most appropriate place to have official requirements to the front-end systems. Only few of a long list of important parameters of the front-end system have officially been decided by the LHCb collaboration: http://lhcb.cern.ch/electronics/html/key_parameters.htm We need to fix these in the near future to enable front-end designs to progress further than just early prototypes. Most important parameters have currently proposed values and it is now a good time to let us know if any of these poses problems for the design of specific parts of the front-end electronics. Many other aspects of the front-end systems must be defined. I have started this by writing some kind of brain storm on a set of important aspects of the front-end. These are accessible from: http://lhcb.cern.ch/electronics and contains the following new web pages: Error checking: required error checking facilities in front-end Interface to DAQ: Interface and data format to DAQ (mainly determined by readout unit) Interface to DCS: Protocol, Downloading parameters, monitoring, error reporting, etc. Design reviews: Reviews to insure correctness of IC ,board and subsystem designs Synchronization: Clocking, Phase alignment, Bunch id, sync to L0 trigger. Crates: Crate types, back plane, precautions for use in cavern Calibration, monitoring and testing: Calibration and monitoring facilities in front-end. In-situ testing of Front-end hardware Grounding: Grounding rules to prevent ground loops Readout supervisor: Required functionality of readout supervisor to control front-end system (very important part of whole front-end system) Use of TTC system: Use of TTC system. Distribution of triggers. Distribution of resets. Additional subjects will be added later, such as: Radiation environment: Waiting for radiation simulations of cavern to be finalized. Location of electronics: Allocation of rack space in cavern for individual sub-detectors Front-end multiplexer: Definition of a common front-end multiplexer module ALL KINDS OF COMMENTS TO THESE WEB PAGES ARE MOST WELCOME !!. Best regards Jorgen