genlib/fifo: clarify we behaviour when writable=0

diff --git a/migen/genlib/fifo.py b/migen/genlib/fifo.py
index 0e4ce54efe720ce4bd66619ebdd8432d0b182cdf..308eb5fc23b5be6abca36a0dc8dfe37c38272bb1 100644 (file)
--- a/migen/genlib/fifo.py
+++ b/migen/genlib/fifo.py
@@ -31,10 +31,10 @@ class _FIFOInterface:
        din : in, width_or_layout
                Input data either flat or Record structured.
        writable : out
-               There is space in the FIFO and `we` can be asserted.
+               There is space in the FIFO and `we` can be asserted to load new data.
        we : in
-               Write enable signal to latch `din` into the FIFO. Only assert if
-               `writable` is asserted.
+               Write enable signal to latch `din` into the FIFO. Does nothing if
+               `writable` is not asserted.
        dout : out, width_or_layout
                Output data, same type as `din`. Only valid if `readable` is
                asserted.