Sending something other than spikes

[Alfonso Yamamoto]

Hi, 

I was wondering if there is some way of sending something other than a spike. For instance a REAL. I am looking into graded spikes. 

Where should I start looking ? Or have you guys have done some work on this already ?

Best regards, 

Alfonso

[Andrew Rowley]

Hi,

This is possible but can be a bit tricky in the current implementation.  The SpiNNaker architecture does allow a payload to be sent with a spike. 

At present, we are using this as a count, which is useful for e.g. Poisson sources where they sometimes send multiple spikes in a single timestep.  That would mean that you would have to first untangle this behaviour (this is in spike_source_poisson.c). 

Once you had done this, you then need to work out how to pass the information into the Spike Processing pipeline.  For this you can look at the multicast_packet_pl_received_callback in spike_processing.c (used when the neuron and synapse processing is done on a single core together) and spike_processing_fast.c (used when the synapse processing is done on a separate core). 

The current system adds the spike to a queue and then this is processed in the DMA processing loop, which reads synapses and then converts the spikes into weights to be added via the ring buffers; these ring buffers handle the delays.  For a graded spike, you might instead need to store the value and the spike together.  In processing, you would then need to consider how delays might be handled, since the ring_buffers gather a sum of weights for a given future time, where this would then lose the spike grade potentially.

That is a rough overview.  Please feel free to ask more questions though!

Andrew :)

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From: spinnak...@googlegroups.com <spinnak...@googlegroups.com> on behalf of Alfonso Yamamoto <alfyama...@gmail.com>
Sent: 24 July 2025 08:55
To: SpiNNaker Users Group <spinnak...@googlegroups.com>
Subject: [SpiNNaker Mailing List] Sending something other than spikes

 

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