Source code for spinnman.messages.scp.impl.sdram_alloc
from spinnman.messages.scp import SCPRequestHeader
from spinnman.messages.scp.abstract_messages \
import AbstractSCPRequest, AbstractSCPResponse
from spinnman.messages.scp.enums \
import AllocFree, SCPCommand, SCPResult
from spinnman.messages.sdp import SDPFlag, SDPHeader
from spinnman.exceptions import SpinnmanUnexpectedResponseCodeException
from spinnman.exceptions import SpinnmanInvalidParameterException
import struct
[docs]class SDRAMAlloc(AbstractSCPRequest):
""" An SCP Request to allocate space in the SDRAM space
"""
def __init__(self, x, y, app_id, size, tag=None):
"""
:param x: The x-coordinate of the chip to allocate on, between 0 and\
255
:type x: int
:param y: The y-coordinate of the chip to allocate on, between 0 and\
255
:type y: int
:param app_id: The id of the application, between 0 and 255
:type app_id: int
:param size: The size in bytes of memory to be allocated
:type size: int
:param tag: the tag for the SDRAM, a 8-bit (chip-wide) tag that can be\
looked up by a SpiNNaker application to discover the address\
of the allocated block. If `0` then no tag is applied.
:type tag: int
"""
if tag is None:
tag = 0
elif not(0 <= tag < 256):
raise SpinnmanInvalidParameterException(
"tag",
"The tag param needs to be between 0 and 255, or None (in "
"which case 0 will be used by default)", str(tag))
AbstractSCPRequest.__init__(
self,
SDPHeader(
flags=SDPFlag.REPLY_EXPECTED, destination_port=0,
destination_cpu=0, destination_chip_x=x,
destination_chip_y=y),
SCPRequestHeader(command=SCPCommand.CMD_ALLOC),
argument_1=(
(app_id << 8) |
AllocFree.ALLOC_SDRAM.value), # @UndefinedVariable
argument_2=size, argument_3=tag)
self._size = size
[docs] def get_scp_response(self):
return _SCPSDRAMAllocResponse(self._size)
class _SCPSDRAMAllocResponse(AbstractSCPResponse):
""" An SCP response to a request to allocate space in SDRAM
"""
def __init__(self, size):
"""
"""
AbstractSCPResponse.__init__(self)
self._size = size
self._base_address = None
def read_data_bytestring(self, data, offset):
""" See\
:py:meth:`spinnman.messages.scp.abstract_scp_response.AbstractSCPResponse.read_data_bytestring`
"""
result = self.scp_response_header.result
if result != SCPResult.RC_OK:
raise SpinnmanUnexpectedResponseCodeException(
"SDRAM Allocation", "CMD_ALLOC", result.name)
self._base_address = struct.unpack_from("<I", data, offset)[0]
# check that the base address is not null (0 in python case) as
# this reflects a issue in the command on spinnaker side
if self._base_address == 0:
raise SpinnmanInvalidParameterException(
"SDRAM Allocation response base address", self._base_address,
"Could not allocate {} bytes of SDRAM".format(self._size))
@property
def base_address(self):
""" The base address allocated, or 0 if none
:rtype: int
"""
return self._base_address