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CAEN V1495 module

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This module has a user fpga on which one can do practically anything you want. The one limitation is a 15ns clock for anything requiring more accurate timing, things will get rather complicated.

Module Manual


It contains the Altera Cyclone   EP 1C20

The basic idea, is to use one or 2 of these to entirely replace the logic circuits currently residing in the nim electronics.

  Cyclone device handbook

  1. fan in, fan outs
  2. logical circuits
  3. delay circuits
  4. mean timers
  5. IO Registers
  6. Triggers
  7. Gate and delay generators



To Do

To provide some sort of graphical interface above the verilog internals so that users can use this gui to produce a diagram for their experiments circuit. This has 2 rather significant benefits:

    • the circuit is by default documented accurately.
    • the circuits are repeatable so long delays setting things up are removed.


Additionally the produced circuit would be translated into a graphical user interface to allow the user to adjust the delays and send certain signals to scopes for debugging purposes. This then requires the verliog to produce registers to store the values of all the delays and the derived gui to know what the register values are and provide interfaces to manipulate their values.

Also the sending of signals to NIM outputs to a scope to allow remote control of the trigger circuit via the Tektronix ethernet enabled scopes.


The basics would be to write verilog to achieve our basic building blocks. We would then need to build verilog files for each of :

  • Gate and delay generator
  • fan in/ fan out
  • mean timer
  • logic and and not (should be trivial
  • level coincidence
  • scaler, maybe

Once we have shown we can implement the desired functionality we then need to figure out putting multiple of these on the chip and whether they can fit on it. If that all works then cool, we have a working system then the problem is sorting out how the user interacts with the verilog and having a nice easy to use gui.


Questions to be answered


  1. How simple is it to create the user interface ( possibly looking like normal NIM electronics)
  2. Can the system allow registers for each delay line. This is important else for a change in the delay another fpga image would have to be created which could be rather slow. These registers would then be editable from the secondary interface built from the initial circuit design.
  3. Can the module allow registers for logic levels for the fan ins analagous to the switches on the le croy modules. This is for a similar reason as point 2.
  4. Is it possible to have a register value for each wire in each part of the circuit, stating which if any NIM scope output to fan the signal to, one could then have a scope permanently plugged into the last 4 NIM outputs and control remotely.  This then would use the gui refered to in point 2 to put a scope on any line. - multiplexors with their selects done via a vme register. each possible line will go into each of the four multiplexors allowing any thing to be routed to the outputs connected to the oscilloscope. Software would store the mappings between reading points and multiplexor select values.  
  5. To create the primary interface for the fpga image generation does on create a gui that manually converts to verilog or do we use something like the qt widget set from to do the circuit design->verilog generation.



Read this :

bsf fpga description


This site contains info on the TDC and Vertex board mods, together with the PROM files for the baords and any other interesting things.


HCAL Trigger Readout


L1 Trigger Equations for the Forward Proton Detector at DZero


Intial Software thoughts and design


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