src/python/gem5/components/memory/simple.py

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"""Simple memory controllers
"""

from ...utils.override import overrides
from m5.util.convert import toMemorySize
from typing import List, Sequence, Tuple
from ..boards.abstract_board import AbstractBoard
from .abstract_memory_system import AbstractMemorySystem
from m5.objects import AddrRange, MemCtrl, Port, SimpleMemory

class SingleChannelSimpleMemory(AbstractMemorySystem):
    """A class to implement single channel memory system using SimpleMemory

    This class takes latency, latency variation, and bandwidth and configures
    a memory with those values. It could be used for studies that do not target
    memory subsystem design.
    """

    def __init__(
        self, latency: str, latency_var: str, bandwidth: str, size: str
    ):
        """
        :param latency: The average of request to response latency.
        :param latency_var: The variance of request to response latency.
        :param bandwidth: Combined read and write bandwidth.
        :param size: Size of the memory.
        """
        super().__init__()

        self.module = SimpleMemory(
            latency=latency, latency_var=latency_var, bandwidth=bandwidth
        )
        self._size = toMemorySize(size)

    @overrides(AbstractMemorySystem)
    def incorporate_memory(self, board: AbstractBoard) -> None:
        pass

    @overrides(AbstractMemorySystem)
    def get_mem_ports(self) -> Sequence[Tuple[AddrRange, Port]]:
        return [(self.module.range, self.module.port)]

    @overrides(AbstractMemorySystem)
    def get_memory_controllers(self) -> List[MemCtrl]:
        return [self.module]

    @overrides(AbstractMemorySystem)
    def get_size(self) -> int:
        return self._size

    @overrides(AbstractMemorySystem)
    def set_memory_range(self, ranges: List[AddrRange]) -> None:
        if len(ranges) != 1 or ranges[0].size() != self._size:
            raise Exception(
                "Simple single channel memory controller requires a single "
                "range which matches the memory's size."
            )
        self.module.range = ranges[0]