Source code for spynnaker.pyNN.utilities.bit_field_utilities

# Copyright (c) 2019 The University of Manchester
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# See the License for the specific language governing permissions and
# limitations under the License.

import math
import numpy
from spinn_front_end_common.utilities.constants import BYTES_PER_WORD
from spinn_utilities.ordered_set import OrderedSet
from spynnaker.pyNN.utilities.constants import SPIKE_PARTITION_ID
from import SpynnakerDataView

#: number of elements
#  key, n atoms, atoms_per_core, pointer to bitfield

#: n_filters, pointer for array

#: the number of bits in a word
BIT_IN_A_WORD = 32.0

[docs] def get_sdram_for_bit_field_region(incoming_projections): """ The SDRAM for the bit field filter region. :param incoming_projections: The projections that target the vertex in question :type incoming_projections: iterable(~spynnaker.pyNN.models.projection.Projection) :return: the estimated number of bytes used by the bit field region :rtype: int """ sdram = FILTER_HEADER_WORDS * BYTES_PER_WORD seen_app_edges = set() for proj in incoming_projections: app_edge = proj._projection_edge # pylint: disable=protected-access if app_edge not in seen_app_edges: seen_app_edges.add(app_edge) n_atoms = app_edge.pre_vertex.n_atoms n_words_for_atoms = int(math.ceil(n_atoms / BIT_IN_A_WORD)) sdram += (FILTER_INFO_WORDS + n_words_for_atoms) * BYTES_PER_WORD # Also add for delay vertices if needed n_words_for_delays = int(math.ceil( n_atoms * app_edge.n_delay_stages / BIT_IN_A_WORD)) sdram += (FILTER_INFO_WORDS + n_words_for_delays) * BYTES_PER_WORD return sdram
[docs] def get_sdram_for_keys(incoming_projections): """ Gets the space needed for keys. :param incoming_projections: The projections that target the vertex in question :type incoming_projections: iterable(~spynnaker.pyNN.models.projection.Projection) :return: SDRAM needed :rtype: int """ # basic sdram sdram = 0 seen_app_edges = set() for proj in incoming_projections: in_edge = proj._projection_edge # pylint: disable=protected-access if in_edge not in seen_app_edges: seen_app_edges.add(in_edge) sdram += BYTES_PER_WORD if in_edge.n_delay_stages: sdram += BYTES_PER_WORD return sdram
[docs] def get_bitfield_key_map_data(incoming_projections): """ Get data for the key map region. :param incoming_projections: The projections to generate bitfields for :type incoming_projections: iterable(~spynnaker.pyNN.models.projection.Projection) :rtype: ~numpy.ndarray """ # Gather the source vertices that target this core routing_infos = SpynnakerDataView.get_routing_infos() sources = OrderedSet() for proj in incoming_projections: # pylint: disable=protected-access in_edge = proj._projection_edge if in_edge not in sources: key = routing_infos.get_first_key_from_pre_vertex( in_edge.pre_vertex, SPIKE_PARTITION_ID) if key is not None: sources.add((key, in_edge.pre_vertex.n_atoms)) if in_edge.delay_edge is not None: delay_key = routing_infos.get_first_key_from_pre_vertex( in_edge.delay_edge.pre_vertex, SPIKE_PARTITION_ID) if delay_key is not None: n_delay_atoms = ( in_edge.pre_vertex.n_atoms * in_edge.n_delay_stages) sources.add((delay_key, n_delay_atoms)) if not sources: return numpy.array([], dtype="uint32") # Make keys and atoms, ordered by keys key_map = numpy.array( [[key, n_atoms] for key, n_atoms in sources], dtype="uint32") key_map = key_map[numpy.argsort(key_map[:, 0])] # get the number of atoms per item return key_map[:, 1]
[docs] def write_bitfield_init_data( spec, bit_field_region, n_bit_field_bytes, bit_field_region_ref=None): """ Writes the initialisation data needed for the bitfield generator. :param ~data_specification.DataSpecificationGenerator spec: data specification writer :param int bit_field_region: the region ID for the bit-field filters :param int n_bit_field_bytes: the size of the region :param int bit_field_region_ref: The reference to the region """ # reserve the final destination for the bitfields spec.reserve_memory_region( region=bit_field_region, size=n_bit_field_bytes, label="bit_field region", reference=bit_field_region_ref) # Ensure a 0 is written at least to indicate no bit fields if not expanded spec.switch_write_focus(bit_field_region) spec.write_value(0)