clarify 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 45bed19301a5c46b3213c8ae0217405182f6a215..0f4fb20cf952cb23fd53d71022e0e0e136c6ee9b 100644 (file)
--- a/src/add/example_buf_pipe.py
+++ b/src/add/example_buf_pipe.py
@@ -110,24 +110,48 @@ class BufferedPipeline:
                                      |           |
                                      +-> r_data -+
         """
-        # input: strobe comes in from previous stage, ready comes in from next
-        self.i = IOAckIn()
-        #self.i.p_valid = Signal()    # >>in - comes in from PREVIOUS stage
-        #self.i.n_ready = Signal()   # in<< - comes in from the NEXT stage
+        self.stage = stage
 
-        # output: strobe goes out to next stage, ready comes in from previous
+        # set up input and output IO ACK (prev/next ready/valid)
+        self.i = IOAckIn()
         self.o = IOAckOut()
-        #self.o.n_valid = Signal()    # out>> - goes out to the NEXT stage
-        #self.o.p_ready = Signal()   # <<out - goes out to the PREVIOUS stage
 
         # set up the input and output data
         self.i.data = stage.ispec() # input type
         self.r_data = stage.ospec() # all these are output type
         self.result = stage.ospec()
         self.o.data = stage.ospec()
-        self.stage = stage
+
+    def connect_next(self, nxt):
+        """ helper function to connect to the next stage data/valid/ready.
+            data/valid is passed *TO* nxt, and ready comes *IN* from nxt.
+        """
+        return [nxt.i.p_valid.eq(self.o.n_valid),
+                self.i.n_ready.eq(nxt.o.p_ready),
+                eq(nxt.i.data, self.o.data),
+               ]
+
+    def connect_in(self, prev):
+        """ helper function to connect stage to an input source.  do not
+            use to connect stage-to-stage!
+        """
+        return [self.i.p_valid.eq(prev.i.p_valid),
+                prev.o.p_ready.eq(self.o.p_ready),
+                eq(self.i.data, prev.i.data),
+               ]
+
+    def connect_out(self, nxt):
+        """ helper function to connect stage to an output source.  do not
+            use to connect stage-to-stage!
+        """
+        return [nxt.o.n_valid.eq(self.o.n_valid),
+                self.i.n_ready.eq(nxt.i.n_ready),
+                eq(nxt.o.data, self.o.data),
+               ]
 
     def set_input(self, i):
+        """ helper function to set the input data
+        """
         return eq(self.i.data, i)
 
     def update_buffer(self):