Docs: Assign remaining word cells to groups

Move todos to correct place.
Add todo for x-prop cells.

docs/source/cell/word_arith.rst

@@ -1,6 +1,8 @@
 Coarse arithmetics
 ------------------
 
+.. todo:: Add information about `$alu`, `$fa`, and `$lcu` cells.
+
 Multiply-accumulate
 ~~~~~~~~~~~~~~~~~~~
 

docs/source/cell/word_binary.rst

@@ -4,6 +4,8 @@
 Binary operators
 ~~~~~~~~~~~~~~~~
 
+.. todo:: Add detail on ``$*x`` cells, `$eqx`, `$nex`, `$bweqx`, `$shiftx`
+
 All binary RTL cells have two input ports ``A`` and ``B`` and one output port
 ``Y``. They also have the following parameters:
 

docs/source/cell/word_formal.rst

@@ -12,3 +12,11 @@ Formal verification cells
    :members:
    :source:
    :linenos:
+
+Formal support cells
+~~~~~~~~~~~~~~~~~~~~
+
+.. autocellgroup:: formal_tag
+   :members:
+   :source:
+   :linenos:

docs/source/cell/word_wire.rst

@@ -0,0 +1,9 @@
+Wire cells
+-------------------------
+
+.. todo:: Add information about `$slice` and `$concat` cells.
+
+.. autocellgroup:: wire
+   :members:
+   :source:
+   :linenos:

docs/source/cell_word.rst

@@ -27,10 +27,10 @@ Simulation models for the RTL cells can be found in the file
    /cell/word_spec
    /cell/word_formal
    /cell/word_debug
+   /cell/word_wire
 
-.. todo:: Add information about `$slice` and `$concat` cells.
-
-.. todo:: Add information about `$alu`, `$fa`, and `$lcu` cells.
+.. this should raise a warning, otherwise there are word-level cells without a
+   'group' tag
 
 .. autocellgroup:: word_other
    :caption: Other word-level cells