Make DriveMode sky130 specific for now

Author: robtaylor

chipflow_lib/platforms/__init__.py

@@ -9,14 +9,16 @@
 from .silicon import SiliconPlatformPort, SiliconPlatform
 from .sim import SimPlatform
 from ._utils import (
-        IO_ANNOTATION_SCHEMA, IOSignature, IOModel, IODriveMode, IOTripPoint, IOModelOptions,
+        IO_ANNOTATION_SCHEMA, IOSignature, IOModel, IOTripPoint, IOModelOptions,
         OutputIOSignature, InputIOSignature, BidirIOSignature,
         )
 from ._packages import PACKAGE_DEFINITIONS
+from ._sky130 import Sky130DriveMode
 
 __all__ = ['IO_ANNOTATION_SCHEMA', 'IOSignature',
-           'IOModel', 'IOModelOptions', 'IODriveMode', 'IOTripPoint',
+           'IOModel', 'IOModelOptions', 'IOTripPoint',
            'OutputIOSignature', 'InputIOSignature', 'BidirIOSignature',
            'SiliconPlatformPort', 'SiliconPlatform',
            'SimPlatform',
+           'Sky130DriveMode',
            'PACKAGE_DEFINITIONS']

chipflow_lib/platforms/_sky130.py

@@ -0,0 +1,21 @@
+from enum import StrEnum, auto
+
+class Sky130DriveMode(StrEnum):
+    """
+    Models the potential drive modes of an IO pad.
+    Depending on process and cell library, these may be statically or dynamically configurable.
+
+    You will get an error if the option is not available with the chosen process and cell library
+    """
+    # Strong pull-up, weak pull-down
+    STRONG_UP_WEAK_DOWN = auto()
+    # Weak pull-up, Strong pull-down
+    WEAK_UP_STRONG_DOWN = auto()
+    # Open drain with strong pull-down
+    OPEN_DRAIN_STRONG_DOWN = auto()
+    # Open drain-with strong pull-up
+    OPEN_DRAIN_STRONG_UP= auto()
+    # Strong pull-up, weak pull-down
+    STRONG_UP_STRONG_DOWN = auto()
+    # Weak pull-up, weak pull-down
+    WEAK_UP_WEAK_DOWN = auto()

chipflow_lib/platforms/_utils.py

@@ -31,6 +31,7 @@
 
 from .. import ChipFlowError, _ensure_chipflow_root, _get_cls_by_reference
 from .._appresponse import AppResponseModel, OmitIfNone
+from ._sky130 import Sky130DriveMode
 
 if TYPE_CHECKING:
     from ..config_models import Config
@@ -58,6 +59,7 @@ class VoltageRange(AppResponseModel):
     max: Annotated[Optional[Voltage], OmitIfNone()] = None
     typical: Annotated[Optional[Voltage], OmitIfNone()] = None
 
+
 class IOTripPoint(StrEnum):
     """
     Models various options for trip points for inputs.
@@ -74,27 +76,8 @@ class IOTripPoint(StrEnum):
     VCORE = auto()
     # CMOS level switching referenced to external reference voltage (e.g. low power mode)
     VREF = auto()
-
-
-class IODriveMode(StrEnum):
-    """
-    Models the potential drive modes of an IO pad.
-    Depending on process and cell library, these may be statically or dynamically configurable.
-
-    You will get an error if the option is not available with the chosen process and cell library
-    """
-    # Strong pull-up, weak pull-down
-    STRONG_UP_WEAK_DOWN = auto()
-    # Weak pull-up, Strong pull-down
-    WEAK_UP_STRONG_DOWN = auto()
-    # Open drain with strong pull-down
-    OPEN_DRAIN_STRONG_DOWN = auto()
-    # Open drain-with strong pull-up
-    OPEN_DRAIN_STRONG_UP= auto()
-    # Strong pull-up, weak pull-down
-    STRONG_UP_STRONG_DOWN = auto()
-    # Weak pull-up, weak pull-down
-    WEAK_UP_WEAK_DOWN = auto()
+    # Schmitt trigger
+    SCHMITT_TRIGGER = auto()
 
 
 IO_ANNOTATION_SCHEMA = str(_chipflow_schema_uri("pin-annotation", 0))
@@ -117,7 +100,7 @@ class IOModelOptions(TypedDict):
         clock_domain: the name of the I/O's clock domain (see `Amaranth.ClockDomain`). NB there is only one of these, so IO with multiple clocks must be split up.
         buffer_in: Should the IO pad have an input buffer?
         buffer_out: Should the IO pad have an output buffer?
-        drive_mode: Drive mode for output
+        sky130_drive_mode: Drive mode for output buffer on sky130
         trip_point: Trip Point configutation for input buffer
         init: The value for the initial values of the port
         init_oe: The value for the initial values of the output enable(s) of the port
@@ -128,7 +111,7 @@ class IOModelOptions(TypedDict):
     clock_domain: NotRequired[str]
     buffer_in: NotRequired[bool]
     buffer_out: NotRequired[bool]
-    drive_mode: NotRequired[IODriveMode]
+    sky130_drive_mode: NotRequired[Sky130DriveMode]
     trip_point: NotRequired[IOTripPoint]
     init: NotRequired[int | bool]
     init_oe: NotRequired[int | bool]

chipflow_lib/platforms/silicon.py

@@ -21,7 +21,8 @@
 from amaranth.hdl._ir import PortDirection
 
 from .. import ChipFlowError
-from ._utils import load_pinlock, PortDesc, Pin, IOModel, IODriveMode, IOTripPoint, Process
+from ._utils import load_pinlock, PortDesc, Pin, IOModel, IOTripPoint, Process
+from ._sky130 import Sky130DriveMode
 
 if TYPE_CHECKING:
     from ..config_models import Config
@@ -198,17 +199,17 @@ class Sky130Port(SiliconPlatformPort):
 
     _DriveMode_map = {
         # Strong pull-up, weak pull-down
-        IODriveMode.STRONG_UP_WEAK_DOWN: 0b011,
+        Sky130DriveMode.STRONG_UP_WEAK_DOWN: 0b011,
         # Weak pull-up, Strong pull-down
-        IODriveMode.WEAK_UP_STRONG_DOWN: 0b010,
+        Sky130DriveMode.WEAK_UP_STRONG_DOWN: 0b010,
         # Open drain with strong pull-down
-        IODriveMode.OPEN_DRAIN_STRONG_DOWN: 0b100,
+        Sky130DriveMode.OPEN_DRAIN_STRONG_DOWN: 0b100,
         # Open drain-with strong pull-up
-        IODriveMode.OPEN_DRAIN_STRONG_UP: 0b101,
+        Sky130DriveMode.OPEN_DRAIN_STRONG_UP: 0b101,
         # Strong pull-up, weak pull-down
-        IODriveMode.STRONG_UP_STRONG_DOWN: 0b110,
+        Sky130DriveMode.STRONG_UP_STRONG_DOWN: 0b110,
         # Weak pull-up, weak pull-down
-        IODriveMode.WEAK_UP_WEAK_DOWN: 0b111
+        Sky130DriveMode.WEAK_UP_WEAK_DOWN: 0b111
     }
 
     _VTrip_map = {
@@ -265,9 +266,9 @@ def __init__(self,
         # Drive mode
         if self.direction in (io.Direction.Output, io.Direction.Bidir):
             if 'drive_mode' in port_desc.iomodel:
-                dm = port_desc.iomodel['drive_mode']
+                dm = Sky130DriveMode(port_desc.iomodel['drive_mode'])
             else:
-                dm = IODriveMode.STRONG_UP_STRONG_DOWN
+                dm = Sky130DriveMode.STRONG_UP_STRONG_DOWN
             dm_init = __class__._DriveMode_map[dm]
             self._gpio_dm = Signal(3, name=f"{self._name}$dm", init=dm_init)
             self._signals.append((self._gpio_dm, PortDirection.Output))