Make oe in SRAMResource optional.

diff --git a/nmigen_boards/dev/sram.py b/nmigen_boards/dev/sram.py
index 4eb4eca723db19ac1632d7a4d7f7e179e432c1a4..14e31ce50c1f3bb6d6d261b06df0f7ff5c7f8cb7 100644 (file)
--- a/nmigen_boards/dev/sram.py
+++ b/nmigen_boards/dev/sram.py
@@ -4,10 +4,12 @@ from nmigen.build import *
 __all__ = ["SRAMResource"]
 
 
-def SRAMResource(*args, cs, oe, we, a, d, dm=None, attrs=None):
+def SRAMResource(*args, cs, oe=None, we, a, d, dm=None, attrs=None):
     io = []
     io.append(Subsignal("cs", PinsN(cs, dir="o", assert_width=1)))
-    io.append(Subsignal("oe", PinsN(oe, dir="o", assert_width=1)))
+    if oe is not None:
+        # Asserted WE# deactivates the D output buffers, so WE# can be used to replace OE#.
+        io.append(Subsignal("oe", PinsN(oe, dir="o", assert_width=1)))
     io.append(Subsignal("we", PinsN(we, dir="o", assert_width=1)))
     io.append(Subsignal("a", Pins(a, dir="o")))
     io.append(Subsignal("d", Pins(d, dir="io")))