ASIC event generator

This is an event generator for an ASIC, developed for the PANDA experiment. I wrote this, because I needed some input for my simulations and check if the logic of the ASIC is doing, what it is supposed to do. Therefore there are many specifics to the chip I'm working on, but maybe you can use some parts of this.

Concept

This script emulates the voltage input of two discriminators (time and energy). They have different threshold, time branch lower than the energy branch. The script produces voltages for the given range of time in discrete steps. Randomly, an event is generated and the according voltage increase is stored in this steps.

Finally, for all stored voltages it is checked if they are above the given threshold levels. Discriminator output DOT = True means voltage higher than threshold for time branch, DOT = False means lower than threshold. If the DOT/DOE values change, the time since the last flip (in ps) is saved to a file. Later in the simulation, these times will be used as wait information between the change of the DOT/DOE states.

Installation / Usage

No special requirements. Python > 2.6 is needed, after that you can run the program with

python generate_asic_data.py <time> [<threads>]

time: Run time in milliseconds.
threads: (Optional) Number of threads, 0 is number of CPU cores. Default: 0

The file creates a directory asic_data_?ms with the run time in ms. Inside the directory DOT/DOE switching information (see concept) is stored for each channel in the format ch?_DOx.dat, while the information about the generated pulses are stored in ch?_trues.dat and ch?_dark.dat.

Configuration

Inside the python document, some parameters are given to configure the emulation process. See the _conf parameter and its comments for details. A selection is also explained here.

Simulation accuracy: By changing the stepping parameter, you can change the step size for simulating the voltage values. Default is 1e-11 s. Remeber: lower values cause a longer simulation time, the change is almost linearly.
Rates: With eventRate and darkRate the rate of events/dark counts per second is defined. Default ist 160 kHz of events and 1 MHz of dark counts.
Thresholds: The threshold of the discriminator is set by tThreshold and eThreshold for the time and energy branch, respectively. Default is 0.5 mV and 10 mV.
Output parameters: There are some parameters defining the saving to files. You may change the directory (directory) and the filenames (filename list). For the directory, you should include a {time:.0f} tag that will be replaced by the run time in milliseconds. Filenames have a {channel:d} tag for the channel number, which should be included as well.

Example output files

Note: Data for first channel, others obviously have the same structure.

ch0_trues.dat / ch0_dark.dat

Data structure:

absolute_time pulse_length

Both values in seconds with 12 decimal places (equals to ps resolution).

Example data (6 events):

0.000006520456 0.000000101280
0.000030262739 0.000000104310
0.000035721378 0.000000081840
0.000045872770 0.000000205050
0.000049860426 0.000000048890
0.000056118203 0.000000061700

ch0_DOT.dat / ch0_DOE.dat