diff --git a/RELEASE_NOTES.rst b/RELEASE_NOTES.rst
index c6ff3f579..79683c13a 100644
--- a/RELEASE_NOTES.rst
+++ b/RELEASE_NOTES.rst
@@ -8,6 +8,10 @@ ARTIQ-6
 
 Highlights:
 
+* Performance improvements:
+  - #1432: SERDES TTL inputs can now detect edges on pulses that are shorter
+    than the RTIO period
+
 Breaking changes:
 
 
diff --git a/artiq/gateware/rtio/phy/ttl_serdes_generic.py b/artiq/gateware/rtio/phy/ttl_serdes_generic.py
index 5e03297fa..5c8456d93 100644
--- a/artiq/gateware/rtio/phy/ttl_serdes_generic.py
+++ b/artiq/gateware/rtio/phy/ttl_serdes_generic.py
@@ -7,7 +7,7 @@ from artiq.gateware.rtio import rtlink
 def _mk_edges(w, direction):
     l = [(1 << i) - 1 for i in range(w)]
     if direction == "rising":
-        l = [2**w - 1 ^ x for x in l]
+        l = [((1 << w) - 1) ^ x for x in l]
     elif direction == "falling":
         pass
     else:
@@ -69,8 +69,8 @@ class InOut(Module):
 
         # Output enable, for interfacing to external buffers.
         self.oe = Signal()
-        # LSB of the input state (for edge detection; arbitrary choice, support for
-        # short pulses will need a more involved solution).
+        # input state exposed for edge_counter: latest serdes sample
+        # support for short pulses will need a more involved solution
         self.input_state = Signal()
 
         # # #
@@ -112,15 +112,16 @@ class InOut(Module):
         i_d = Signal()
         self.sync.rio_phy += [
             i_d.eq(i),
-            self.rtlink.i.stb.eq(
-                sample |
-                (sensitivity[0] & ( i & ~i_d)) |
-                (sensitivity[1] & (~i &  i_d))
-            ),
             self.rtlink.i.data.eq(i),
         ]
 
         pe = PriorityEncoder(serdes_width)
         self.submodules += pe
-        self.comb += pe.i.eq(serdes.i ^ Replicate(i_d, serdes_width))
-        self.sync.rio_phy += self.rtlink.i.fine_ts.eq(pe.o)
+        self.comb += pe.i.eq(
+            (serdes.i ^ Cat(i_d, serdes.i)) & (
+                (serdes.i & Replicate(sensitivity[0], serdes_width)) |
+                (~serdes.i & Replicate(sensitivity[1], serdes_width))))
+        self.sync.rio_phy += [
+            self.rtlink.i.fine_ts.eq(pe.o),
+            self.rtlink.i.stb.eq(sample | ~pe.n),
+        ]