Working with an FPGA to Count Coidncident Pulses

  • Thread starter Thread starter dthomas
  • Start date Start date
  • Tags Tags
    Count Fpga
Click For Summary
SUMMARY

This discussion focuses on programming a Basys2 FPGA using VHDL to create a coincidence counting module that accurately counts coincident pulses from two photon counters. The challenge arises from the timing discrepancies in pulse arrival due to wiring imperfections. The solution involves implementing a time window mechanism to ensure that pulses occurring within a specified duration are counted as coincident, utilizing monostables to stretch the pulses to avoid missing short-duration signals.

PREREQUISITES
  • Understanding of FPGA programming, specifically with Basys2.
  • Familiarity with VHDL for hardware description.
  • Knowledge of pulse signal characteristics and timing analysis.
  • Experience with monostable multivibrators for pulse stretching.
NEXT STEPS
  • Research VHDL techniques for implementing time window logic in FPGA designs.
  • Explore the use of monostable multivibrators in digital signal processing.
  • Learn about timing analysis and pulse width measurement in FPGA applications.
  • Investigate coincidence counting algorithms for high-speed signal processing.
USEFUL FOR

Engineers and developers working with FPGAs, particularly those involved in signal processing and timing applications, as well as researchers in photon detection and coincidence counting methodologies.

dthomas
Messages
4
Reaction score
0
I am currently trying to program an FPGA to mimic a coincidence counting module. What I basically need it to do is a modified AND operation. The inputs are square, 5V pulses from photon counters. Because I am working with two photon counters (that are the same model) but due to imperfections in the wiring and their internal circuits, pulses that are emitted from both from the same event might not be arriving at my FPGA at the same exact time.

What I was wondering was if anyone knew create a time window so that the programmable AND logic will count any two pulses that occur within a set time window as the same? I know that if the pulses are a long enough, that any AND gate will return true if the pulses are overlapping at any point, but some of the pulses are as short as a few nano seconds so I want to make sure my design doesn't miss those.

Thanks for the help, oh and if it matters I am using a Basys2 FPGA and I am programming it using VHDL in Xilinx
 
Engineering news on Phys.org
I'd just use monostables to stretch the pulses to whatever is your desired "non overlap window" and then and them together.
 

Similar threads

FPGA Troubleshooting: Spartan 3E-1600 MicroBlaze Dev Board
  • · Replies 4 ·
Replies
4
Views
3K
Which Course to Choose: FPGA with VHDL or Control Systems Design?
  • · Replies 5 ·
Replies
5
Views
3K
Solving the Debate Over Photon Counting With a Scintillation Device
  • · Replies 7 ·
Replies
7
Views
3K
Help with 4017 Circuit for 8V IR Sensor Pulse Counting
  • · Replies 1 ·
Replies
1
Views
2K
How Can I Improve Voltage Range in Photodiode Amplification for Fringe Counting?
  • · Replies 4 ·
Replies
4
Views
4K
Pulsed wideband SNR problem solved by a dynamic carrier?
  • · Replies 2 ·
Replies
2
Views
2K
Graduate Relative efficiency of SHG vs SFG
  • · Replies 6 ·
Replies
6
Views
2K
Graduate Determining MDA for the Dual Label Counting method with the LSC
  • · Replies 0 ·
Replies
0
Views
3K
Creating a timer that performs an action
  • · Replies 5 ·
Replies
5
Views
2K
Graduate Thought experiments suggest problem with published work
  • · Replies 8 ·
Replies
8
Views
2K