#!/usr/bin/env python3 """The `.memories` file format: a JSON inventory of memory macros. One `.memories` file (and the flow-generated `memories.json`) describes memories at the module boundary: geometry, the full pin list with each pin's function, the behavioral model the RTL provides, and whether the memory is converted to a macro (`idiomatic`). The file-based handoff is deliberate: everything downstream — synthesis blackboxing, liberty/LEF consumption in later stages, build systems that declare flow artifacts as transitive dependencies — keys off these files rather than off in-process state. """ from __future__ import annotations import json from dataclasses import asdict, dataclass, field from pathlib import Path SCHEMA_VERSION = 1 PIN_FUNCTIONS = ("addr", "en", "wmode", "mask", "data_in", "data_out", "clk") DIRECTIONS = ("input", "output") class SchemaError(ValueError): pass @dataclass class Pin: name: str direction: str # "input" / "output" width: int port_id: str # "R0", "W1", "RW0", ... function: str # one of PIN_FUNCTIONS @dataclass class Memory: name: str rows: int = 0 bits: int = 0 addr_w: int = 0 read_ports: int = 0 write_ports: int = 0 rw_ports: int = 0 # Total width of the per-port write mask, 0 if unmasked. Subword-split # mask pins (`W0_mask_0..3`) contribute one lane each. mask_lanes: int = 0 pins: list[Pin] = field(default_factory=list) # The module whose RTL body simulates this memory: {"file", "module"}. behavioral_model: dict | None = None # True when the memory is converted to a macro (.lib/.lef emitted and # the module blackboxed); False leaves it to synthesize as flops. idiomatic: bool = False reason: str = "" def total_ports(self) -> int: return self.read_ports + self.write_ports + self.rw_ports def to_dict(self) -> dict: return asdict(self) def _pin_from_dict(d: dict) -> Pin: if not isinstance(d, dict): raise SchemaError("expected a dictionary for pin record") try: pin = Pin( name=d["name"], direction=d["direction"], width=int(d["width"]), port_id=d["port_id"], function=d["function"], ) except KeyError as e: raise SchemaError(f"pin record missing field {e}") from e if pin.direction not in DIRECTIONS: raise SchemaError(f"pin {pin.name}: bad direction '{pin.direction}'") if pin.function not in PIN_FUNCTIONS: raise SchemaError( f"pin {pin.name}: unknown function " f"'{pin.function}' (expected one of " f"{', '.join(PIN_FUNCTIONS)})" ) if pin.width < 1: raise SchemaError(f"pin {pin.name}: width must be >= 1") if not pin.port_id: raise SchemaError(f"pin {pin.name}: empty port_id") return pin def memory_from_dict(d: dict) -> Memory: if not isinstance(d, dict): raise SchemaError("expected a dictionary for memory record") if "name" not in d: raise SchemaError("memory record missing 'name'") mem = Memory(name=d["name"]) for key in ( "rows", "bits", "addr_w", "read_ports", "write_ports", "rw_ports", "mask_lanes", ): if key in d: setattr(mem, key, int(d[key])) if "pins" in d: mem.pins = [_pin_from_dict(p) for p in d["pins"]] if "behavioral_model" in d: mem.behavioral_model = d["behavioral_model"] if "idiomatic" in d: mem.idiomatic = bool(d["idiomatic"]) if "reason" in d: mem.reason = str(d["reason"]) return mem def load(path: Path) -> list[Memory]: """Load a .memories / memories.json file. We expect the JSON file to be valid and readable. If it is not, uncaught exceptions (e.g. FileNotFoundError, JSONDecodeError) provide full detailed stack traces and debug information. """ doc = json.loads(path.read_text()) if not isinstance(doc, dict) or "memories" not in doc: raise SchemaError(f"{path}: expected an object with a 'memories' list") version = doc.get("version", SCHEMA_VERSION) if version != SCHEMA_VERSION: raise SchemaError(f"{path}: unsupported schema version {version}") return [memory_from_dict(m) for m in doc["memories"]] def dump(memories: list[Memory], path: Path, platform: str) -> None: doc = { "version": SCHEMA_VERSION, "platform": platform, "memories": [m.to_dict() for m in sorted(memories, key=lambda m: m.name)], } path.write_text(json.dumps(doc, indent=2) + "\n") def merge(detected: list[Memory], overrides: list[Memory]) -> list[Memory]: """Merge user-supplied entries onto the detected set. An override naming a detected memory replaces only the fields it carries (geometry and pins are kept from detection unless the override provides its own). An override naming an unknown memory is taken whole — it must then carry pins and geometry itself to be emittable. """ by_name = {m.name: m for m in detected} for o in overrides: base = by_name.get(o.name) if base is None: by_name[o.name] = o continue if o.pins: base.pins = o.pins for key in ( "rows", "bits", "addr_w", "read_ports", "write_ports", "rw_ports", "mask_lanes", ): value = getattr(o, key) if value: setattr(base, key, value) if o.behavioral_model is not None: base.behavioral_model = o.behavioral_model if o.idiomatic: base.idiomatic = True if o.reason: base.reason = o.reason return list(by_name.values()) def validate_emittable(mem: Memory) -> None: """Raise SchemaError unless `mem` carries enough to emit .lib/.lef.""" if not mem.pins: raise SchemaError(f"memory {mem.name}: no pins") if mem.rows < 1 or mem.bits < 1: raise SchemaError( f"memory {mem.name}: rows ({mem.rows}) and bits ({mem.bits}) " f"must be >= 1" ) port_ids = {p.port_id for p in mem.pins} for port_id in port_ids: functions = {p.function for p in mem.pins if p.port_id == port_id} if "clk" not in functions: raise SchemaError(f"memory {mem.name}: port {port_id} has no clk pin") if "addr" not in functions: raise SchemaError(f"memory {mem.name}: port {port_id} has no addr pin") if not functions & {"data_in", "data_out"}: raise SchemaError(f"memory {mem.name}: port {port_id} has no data pin")