From: William D. Jones <thor0505@comcast.net>
Date: Sun, 4 Aug 2019 13:32:34 +0000 (-0400)
Subject: Make oe in SRAMResource optional.
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=9b532bef934020cdf25dbcd9eee8bd5b973a8186;p=nmigen-boards.git

Make oe in SRAMResource optional.
---

diff --git a/nmigen_boards/dev/sram.py b/nmigen_boards/dev/sram.py
index 4eb4eca..14e31ce 100644
--- 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")))