add notes on FunctionUnit API

[soc.git] / src / soc / fu / compunits.py

diff --git a/src/soc/fu/compunits.py b/src/soc/fu/compunits.py
new file mode 100644 (file)
index 0000000..68d42d8
--- /dev/null
+++ b/src/soc/fu/compunits.py
@@ -0,0 +1,63 @@
+"""
+* see https://libre-soc.org/3d_gpu/architecture/regfile/ section on regspecs
+
+"""
+
+from nmigen.cli import rtlil
+from soc.experiment.compalu_multi import MultiCompUnit
+
+from soc.fu.alu.pipeline import ALUBasePipe
+from soc.fu.alu.pipe_data import ALUPipeSpec
+
+from soc.fu.cr.pipeline import CRBasePipe
+from soc.fu.cr.pipe_data import CRPipeSpec
+
+
+class FunctionUnitBaseSingle(MultiCompUnit):
+    """FunctionUnitBaseSingle
+
+    main "glue" class that brings everything together.
+    ONLY use this class for single-stage pipelines.
+
+    * :speckls:  - the specification.  contains regspec and op subset info,
+                   and contains common "stuff" like the pipeline ctx,
+                   what type of nmutil pipeline base is to be used (etc)
+    * :pipekls:  - the type of pipeline.  actually connects things together
+
+    note that it is through MultiCompUnit.get_in/out that we *actually*
+    connect up the association between regspec variable names (defined
+    in the pipe_data).
+    """
+    def __init__(self, speckls, pipekls):
+        pspec = speckls(id_wid=2)                # spec (NNNPipeSpec instance)
+        opsubset = pspec.opsubsetkls             # get the operand subset class
+        regspec = pspec.regspec                  # get the regspec
+        alu = pipekls(pspec)                     # create actual NNNBasePipe
+        super().__init__(regspec, alu, opsubset) # pass to MultiCompUnit
+
+
+######################################################################
+###### actual Function Units: these are "single" stage pipelines #####
+
+class ALUFunctionUnit(FunctionUnitBaseSingle):
+    def __init__(self): super().__init__(ALUPipeSpec, ALUBasePipe)
+
+class CRFunctionUnit(FunctionUnitBaseSingle):
+    def __init__(self): super().__init__(CRPipeSpec, CRBasePipe)
+
+#####################################################################
+###### actual Function Units: these are "multi" stage pipelines #####
+
+# TODO: ReservationStations-based.
+
+
+def tst_single_fus_il():
+    for (name, kls) in (('alu', ALUFunctionUnit),
+                        ('cr', CRFunctionUnit)):
+        fu = kls()
+        vl = rtlil.convert(fu, ports=fu.ports())
+        with open("fu_%s.il" % name, "w") as f:
+            f.write(vl)
+
+if __name__ == '__main__':
+    tst_single_fus_il()