update comments

[ieee754fpu.git] / src / add / example_buf_pipe.py

diff --git a/src/add/example_buf_pipe.py b/src/add/example_buf_pipe.py
index 52568b5a0621ea1e440289697a8a38ae5be2380b..6c310b0393d90fd4a99d4e191ac19562b2bd9b26 100644 (file)
--- a/src/add/example_buf_pipe.py
+++ b/src/add/example_buf_pipe.py
@@ -45,6 +45,8 @@
 
 from nmigen import Signal, Cat, Const, Mux, Module
 from nmigen.cli import verilog, rtlil
+from nmigen.hdl.rec import Record, Layout
+
 from collections.abc import Sequence
 
 
@@ -56,8 +58,8 @@ class PrevControl:
     """
 
     def __init__(self):
-        self.i_valid = Signal(name="p_i_valid") # >>in
-        self.o_ready = Signal(name="p_o_ready") # <<out
+        self.i_valid = Signal(name="p_i_valid") # prev   >>in  self
+        self.o_ready = Signal(name="p_o_ready") # prev   <<out self
 
     def connect_in(self, prev):
         """ helper function to connect stage to an input source.  do not
@@ -76,8 +78,8 @@ class NextControl:
         * o_data : an output - added by the user of this class
     """
     def __init__(self):
-        self.o_valid = Signal(name="n_o_valid") # out>>
-        self.i_ready = Signal(name="n_i_ready") # <<in
+        self.o_valid = Signal(name="n_o_valid") # self out>>  next
+        self.i_ready = Signal(name="n_i_ready") # self <<in   next
 
     def connect_to_next(self, nxt):
         """ helper function to connect to the next stage data/valid/ready.
@@ -102,12 +104,31 @@ def eq(o, i):
     """ makes signals equal: a helper routine which identifies if it is being
         passsed a list (or tuple) of objects, and calls the objects' eq
         function.
+
+        complex objects (classes) can be used: they must follow the
+        convention of having an eq member function, which takes the
+        responsibility of further calling eq and returning a list of
+        eq assignments
+
+        Record is a special (unusual, recursive) case, where the input
+        is specified as a dictionary (which may contain further dictionaries,
+        recursively), where the field names of the dictionary must match
+        the Record's field spec.
     """
     if not isinstance(o, Sequence):
         o, i = [o], [i]
     res = []
     for (ao, ai) in zip(o, i):
-        res.append(ao.eq(ai))
+        #print ("eq", ao, ai)
+        if isinstance(ao, Record):
+            for idx, (field_name, field_shape, _) in enumerate(ao.layout):
+                if isinstance(field_shape, Layout):
+                    rres = eq(ao.fields[field_name], ai.fields[field_name])
+                else:
+                    rres = eq(ao.fields[field_name], ai[field_name])
+                res += rres
+        else:
+            res.append(ao.eq(ai))
     return res
 
 
@@ -116,10 +137,11 @@ class PipelineBase:
     """
     def __init__(self, stage):
         """ pass in a "stage" which may be either a static class or a class
-            instance, which has three functions:
+            instance, which has four functions (one optional):
             * ispec: returns input signals according to the input specification
             * ispec: returns output signals to the output specification
             * process: takes an input instance and returns processed data
+            * setup: performs any module linkage if the stage uses one.
 
             User must also:
             * add i_data member to PrevControl and
@@ -156,7 +178,7 @@ class PipelineBase:
     def ports(self):
         return [self.p.i_valid, self.n.i_ready,
                 self.n.o_valid, self.p.o_ready,
-                self.p.i_data, self.n.o_data
+                self.p.i_data, self.n.o_data   # XXX need flattening!
                ]
 
 
@@ -308,24 +330,15 @@ class CombPipe(PipelineBase):
     """A simple pipeline stage containing combinational logic that can execute
     completely in one clock cycle.
 
-    Parameters:
-    -----------
-    input_shape : int or tuple or None
-        the shape of ``input.data`` and ``comb_input``
-    output_shape : int or tuple or None
-        the shape of ``output.data`` and ``comb_output``
-    name : str
-        the name
-
     Attributes:
     -----------
     input : StageInput
         The pipeline input
     output : StageOutput
         The pipeline output
-    comb_input : Signal, input_shape
-        The input to the combinatorial logic
-    comb_output: Signal, output_shape
+    r_data : Signal, input_shape
+        A temporary (buffered) copy of a prior (valid) input
+    result: Signal, output_shape
         The output of the combinatorial logic
     """