synapses.c File Reference

Implementation of non-inlined API in synapses.h. More...

#include "synapses.h"
#include "spike_processing.h"
#include "neuron.h"
#include "plasticity/synapse_dynamics.h"
#include <profiler.h>
#include <debug.h>
#include <spin1_api.h>
#include <utils.h>

Go to the source code of this file.

Data Structures
struct	synapse_params
	The layout of the synapse parameters region. More...

Functions
static const char *	get_type_char (uint32_t synapse_type)
	get the synapse type character
static void	print_synaptic_row (synaptic_row_t synaptic_row)
	Print a synaptic row.
static void	print_ring_buffers (uint32_t time)
	Print the contents of the ring buffers.
static bool	process_fixed_synapses (synapse_row_fixed_part_t *fixed_region, uint32_t time, uint32_t colour_delay)
	The "inner loop" of the neural simulation.
bool	synapses_initialise (address_t synapse_params_address, uint32_t *n_neurons_out, uint32_t *n_synapse_types_out, weight_t **ring_buffers_out, uint32_t **ring_buffer_to_input_buffer_left_shifts, bool *clear_input_buffers_of_late_packets_init, uint32_t *incoming_spike_buffer_size)
	Initialise the synapse processing.
void	synapses_flush_ring_buffers (timer_t time)
	Reset the ring buffers to 0 at the given time.
bool	synapses_process_synaptic_row (uint32_t time, uint32_t spike_colour, uint32_t colour_mask, synaptic_row_t row, bool *write_back)
	process a synaptic row
uint32_t	synapses_get_pre_synaptic_events (void)
	returns the counters for plastic and fixed pre synaptic events based on (if the model was compiled with SYNAPSE_BENCHMARK parameter) or returns 0
void	synapses_resume (timer_t time)
	Resume processing of synapses after a pause.

Variables
uint32_t	num_fixed_pre_synaptic_events = 0
	if using profiler import profiler tags
static uint32_t	n_neurons
	The number of neurons.
static uint32_t	n_synapse_types
	The number of synapse types.
static weight_t *	ring_buffers
	Ring buffers to handle delays between synapses and neurons.
static uint32_t	ring_buffer_size
	Ring buffer size.
static uint32_t	ring_buffer_mask
	Ring buffer mask.
static uint32_t *	ring_buffer_to_input_left_shifts
	Amount to left shift the ring buffer by to make it an input.
uint32_t	synapse_type_index_bits
	Number of bits needed for the synapse type and index.
uint32_t	synapse_type_index_mask
	Mask to pick out the synapse type and index.
uint32_t	synapse_index_bits
	Number of bits in the synapse index.
uint32_t	synapse_index_mask
	Mask to pick out the synapse index.
uint32_t	synapse_type_bits
	Number of bits in the synapse type.
uint32_t	synapse_type_mask
	Mask to pick out the synapse type.
uint32_t	synapse_delay_bits
	Number of bits in the delay.
uint32_t	synapse_delay_mask
	Mask to pick out the delay.
uint32_t	synapses_saturation_count = 0
	Count of the number of times the ring buffers have saturated.
uint32_t	skipped_synapses = 0
uint32_t	late_spikes = 0
	Count of the spikes that are received late.
uint32_t	max_late_spike = 0
	The maximum lateness of a spike.
static uint32_t	n_neurons_peak
	Number of neurons.
static uint32_t	synapse_delay_mask_shifted = 0
	The mask of the delay shifted into position i.e. pre-shift.

Detailed Description

Implementation of non-inlined API in synapses.h.

Definition in file synapses.c.

---

Data Structure Documentation

synapse_params

struct synapse_params

The layout of the synapse parameters region.

Definition at line 256 of file synapses.c.

Data Fields
uint32_t	n_neurons
uint32_t	n_synapse_types
uint32_t	log_n_neurons
uint32_t	log_n_synapse_types
uint32_t	log_max_delay
uint32_t	drop_late_packets
uint32_t	incoming_spike_buffer_size
uint32_t	ring_buffer_shifts[]

Function Documentation

get_type_char()

static const char * get_type_char ( uint32_t  synapse_type )

inlinestatic

get the synapse type character

Parameters

[in]

synapse_type

the synapse type

Returns

a single character string describing the synapse type

Definition at line 105 of file synapses.c.

print_synaptic_row()

static void print_synaptic_row ( synaptic_row_t  synaptic_row )

inlinestatic

Print a synaptic row.

Only does anything when debugging.

Parameters

[in]

synaptic_row

The synaptic row to print

Definition at line 114 of file synapses.c.

print_ring_buffers()

static void print_ring_buffers ( uint32_t  time )

inlinestatic

Print the contents of the ring buffers.

Only does anything when debugging.

Parameters

[in]

time

The current timestamp

Definition at line 165 of file synapses.c.

process_fixed_synapses()

static bool process_fixed_synapses ( synapse_row_fixed_part_t *  fixed_region, uint32_t  time, uint32_t  colour_delay  )

inlinestatic

The "inner loop" of the neural simulation.

Every spike event could cause up to 256 different weights to be put into the ring buffer.

Parameters

[in]	fixed_region	The fixed region of the synaptic matrix
[in]	time	The current simulation time

Returns

Always true

Definition at line 206 of file synapses.c.

synapses_initialise()

bool synapses_initialise	(	address_t	synapse_params_address,
		uint32_t *	n_neurons,
		uint32_t *	n_synapse_types,
		weight_t **	ring_buffers,
		uint32_t **	ring_buffer_to_input_buffer_left_shifts,
		bool *	clear_input_buffers_of_late_packets_init,
		uint32_t *	incoming_spike_buffer_size
	)

Initialise the synapse processing.

Parameters

[in]	synapse_params_address	Synapse configuration in SDRAM
[out]	n_neurons	Number of neurons that will be simulated
[out]	n_synapse_types	Number of synapse types that will be simulated
[out]	ring_buffers	The ring buffers that will be used
[out]	ring_buffer_to_input_buffer_left_shifts	Array of shifts to use when converting from ring buffer values to input buffer values
[out]	clear_input_buffers_of_late_packets_init	Inicates whether to clear the input buffers each time step
[out]	incoming_spike_buffer_size	The number of spikes to support in the incoming spike circular buffer

Returns

True if successfully initialised. False otherwise.

Definition at line 268 of file synapses.c.

synapses_flush_ring_buffers()

void synapses_flush_ring_buffers

(

timer_t

time

)

Reset the ring buffers to 0 at the given time.

Parameters

[in]

time

the simulated time to reset the buffers at

Definition at line 336 of file synapses.c.

synapses_process_synaptic_row()

bool synapses_process_synaptic_row	(	uint32_t	time,
		uint32_t	spike_colour,
		uint32_t	colour_mask,
		synaptic_row_t	row,
		bool *	write_back
	)

process a synaptic row

Parameters

[in]	time	the simulated time
[in]	spike_colour	the colour extracted from the spike key
[in]	colour_mask	the colour mask extracted from the pop table
[in]	row	the synaptic row in question
[out]	write_back	whether to write back to SDRAM

Returns

True if successful

Definition at line 351 of file synapses.c.

synapses_get_pre_synaptic_events()

uint32_t synapses_get_pre_synaptic_events

(

void

)

returns the counters for plastic and fixed pre synaptic events based on (if the model was compiled with SYNAPSE_BENCHMARK parameter) or returns 0

Returns

the counter for plastic and fixed pre synaptic events or 0

Definition at line 405 of file synapses.c.

synapses_resume()

void synapses_resume

(

timer_t

time

)

Resume processing of synapses after a pause.

Parameters

[in]

time

The time at which the simulation is to start

Definition at line 410 of file synapses.c.

Variable Documentation

num_fixed_pre_synaptic_events

uint32_t num_fixed_pre_synaptic_events = 0

if using profiler import profiler tags

Globals required for synapse benchmarking to work.

Definition at line 34 of file synapses.c.

n_neurons

uint32_t n_neurons

static

The number of neurons.

Definition at line 37 of file synapses.c.

n_synapse_types

uint32_t n_synapse_types

static

The number of synapse types.

Definition at line 40 of file synapses.c.

ring_buffers

weight_t* ring_buffers

static

Ring buffers to handle delays between synapses and neurons.

Definition at line 43 of file synapses.c.

ring_buffer_size

uint32_t ring_buffer_size

static

Ring buffer size.

Definition at line 46 of file synapses.c.

ring_buffer_mask

uint32_t ring_buffer_mask

static

Ring buffer mask.

Definition at line 49 of file synapses.c.

ring_buffer_to_input_left_shifts

uint32_t* ring_buffer_to_input_left_shifts

static

Amount to left shift the ring buffer by to make it an input.

Definition at line 52 of file synapses.c.

synapse_type_index_bits

uint32_t synapse_type_index_bits

Number of bits needed for the synapse type and index.

The number of bits used by the synapse type and post-neuron index.

synapse_index_bits + synapse_type_bits

Definition at line 59 of file synapses.c.

synapse_type_index_mask

uint32_t synapse_type_index_mask

Mask to pick out the synapse type and index.

synapse_index_mask | synapse_type_mask

Definition at line 65 of file synapses.c.

synapse_index_bits

uint32_t synapse_index_bits

Number of bits in the synapse index.

The number of bits used by just the post-neuron index.

Definition at line 67 of file synapses.c.

synapse_index_mask

uint32_t synapse_index_mask

Mask to pick out the synapse index.

Definition at line 69 of file synapses.c.

synapse_type_bits

uint32_t synapse_type_bits

Number of bits in the synapse type.

Definition at line 71 of file synapses.c.

synapse_type_mask

uint32_t synapse_type_mask

Mask to pick out the synapse type.

Definition at line 73 of file synapses.c.

synapse_delay_bits

uint32_t synapse_delay_bits

Number of bits in the delay.

Definition at line 75 of file synapses.c.

synapse_delay_mask

uint32_t synapse_delay_mask

Mask to pick out the delay.

The mask to get the synaptic delay from a "synapse".

Definition at line 77 of file synapses.c.

synapses_saturation_count

uint32_t synapses_saturation_count = 0

Count of the number of times the ring buffers have saturated.

Count of the number of times the synapses have saturated their weights.

Definition at line 80 of file synapses.c.

skipped_synapses

uint32_t skipped_synapses = 0

Count of the synapses that have been skipped because the delay wasn't big enough given how long the spike took to arrive

Definition at line 84 of file synapses.c.

late_spikes

uint32_t late_spikes = 0

Count of the spikes that are received late.

Definition at line 87 of file synapses.c.

max_late_spike

uint32_t max_late_spike = 0

The maximum lateness of a spike.

Definition at line 90 of file synapses.c.

n_neurons_peak

uint32_t n_neurons_peak

static

Number of neurons.

Definition at line 93 of file synapses.c.

synapse_delay_mask_shifted

uint32_t synapse_delay_mask_shifted = 0

static

The mask of the delay shifted into position i.e. pre-shift.

Definition at line 96 of file synapses.c.