diff --git a/examples/usb/superspeed/simple_device.py b/examples/usb/superspeed/simple_device.py
index 71cb5769f..814c75302 100755
--- a/examples/usb/superspeed/simple_device.py
+++ b/examples/usb/superspeed/simple_device.py
@@ -6,7 +6,6 @@
 # SPDX-License-Identifier: BSD-3-Clause
 
 from amaranth import *
-from amaranth.hdl.ast import Fell
 
 from usb_protocol.emitters         import SuperSpeedDeviceDescriptorCollection
 
diff --git a/examples/usb/superspeed/stream_in_device.py b/examples/usb/superspeed/stream_in_device.py
index c05f2cd22..85165f084 100755
--- a/examples/usb/superspeed/stream_in_device.py
+++ b/examples/usb/superspeed/stream_in_device.py
@@ -6,7 +6,6 @@
 # SPDX-License-Identifier: BSD-3-Clause
 
 from amaranth import *
-from amaranth.hdl.ast import Fell
 
 from usb_protocol.emitters         import SuperSpeedDeviceDescriptorCollection
 
diff --git a/examples/usb/superspeed/vendor_request.py b/examples/usb/superspeed/vendor_request.py
index 0e8e51078..4c223a3d6 100755
--- a/examples/usb/superspeed/vendor_request.py
+++ b/examples/usb/superspeed/vendor_request.py
@@ -6,7 +6,6 @@
 # SPDX-License-Identifier: BSD-3-Clause
 
 from amaranth import *
-from amaranth.hdl.ast import Fell
 
 from usb_protocol.types            import USBRequestType
 from usb_protocol.emitters         import SuperSpeedDeviceDescriptorCollection
diff --git a/luna/gateware/debug/ila.py b/luna/gateware/debug/ila.py
index edfc68bf5..3081b2f2b 100644
--- a/luna/gateware/debug/ila.py
+++ b/luna/gateware/debug/ila.py
@@ -17,7 +17,6 @@
 from abc               import ABCMeta, abstractmethod
 
 from amaranth          import Signal, Module, Cat, Elaboratable, Memory, ClockDomain, DomainRenamer
-from amaranth.hdl.ast  import Rose
 from amaranth.lib.cdc  import FFSynchronizer
 from amaranth.lib.fifo import AsyncFIFOBuffered
 from vcd               import VCDWriter
@@ -376,7 +375,10 @@ def elaborate(self, platform):
         m  = Module()
         m.submodules.ila = self.ila
 
-        transaction_start = Rose(self.spi.cs)
+        # Keep track of the rising edge of the CS signal
+        past_spi_cs       = Signal()
+        m.d.sync         += past_spi_cs.eq(self.spi.cs)
+        transaction_start = ~past_spi_cs & self.spi.cs 
 
         # Connect up our SPI transciever to our public interface.
         interface = SPIDeviceInterface(
diff --git a/luna/gateware/interface/gateware_phy/phy.py b/luna/gateware/interface/gateware_phy/phy.py
index 950871276..106c56547 100644
--- a/luna/gateware/interface/gateware_phy/phy.py
+++ b/luna/gateware/interface/gateware_phy/phy.py
@@ -6,7 +6,6 @@
 import logging
 
 from amaranth         import Signal, Module, Cat, Elaboratable, ClockSignal
-from amaranth.hdl.ast import Rose, Past
 
 from .receiver      import RxPipeline
 from .transmitter   import TxPipeline
diff --git a/luna/gateware/interface/gateware_phy/receiver.py b/luna/gateware/interface/gateware_phy/receiver.py
index 40b7f0e9c..298fde3cc 100644
--- a/luna/gateware/interface/gateware_phy/receiver.py
+++ b/luna/gateware/interface/gateware_phy/receiver.py
@@ -34,7 +34,6 @@
 
 from amaranth          import Elaboratable, Module, Signal, Cat, Const, ClockSignal
 from amaranth.lib.fifo import AsyncFIFOBuffered
-from amaranth.hdl.ast  import Past
 from amaranth.hdl.xfrm import ResetInserter
 
 from ...utils.cdc import synchronize
@@ -622,10 +621,12 @@ def elaborate(self, platform):
         # 1bit->8bit (1byte) gearing
         #
         m.submodules.shifter = shifter = RxShifter(width=8)
+        past_o_pkt_active    = Signal()
+        m.d.usb_io          += past_o_pkt_active.eq(detect.o_pkt_active)
         m.d.comb += [
             shifter.reset.eq(detect.o_pkt_end),
             shifter.i_data.eq(bitstuff.o_data),
-            shifter.i_valid.eq(~bitstuff.o_stall & Past(detect.o_pkt_active, domain="usb_io")),
+            shifter.i_valid.eq(~bitstuff.o_stall & past_o_pkt_active),
         ]
 
         #
diff --git a/luna/gateware/interface/spi.py b/luna/gateware/interface/spi.py
index ead2b44d6..693dc0962 100644
--- a/luna/gateware/interface/spi.py
+++ b/luna/gateware/interface/spi.py
@@ -9,7 +9,6 @@
 import unittest
 
 from amaranth import Signal, Module, Cat, Elaboratable, Record
-from amaranth.hdl.ast import Rose, Fell
 from amaranth.hdl.rec import DIR_FANIN, DIR_FANOUT
 
 from ..test.utils import LunaGatewareTestCase, sync_test_case
@@ -85,8 +84,10 @@ def spi_edge_detectors(self, m):
         # Generate the leading and trailing edge detectors.
         # Note that we use rising and falling edge detectors, but call these leading and
         # trailing edges, as our clock here may have been inverted.
-        leading_edge  = Rose(serial_clock, domain="sync")
-        trailing_edge = Fell(serial_clock, domain="sync")
+        past_clk      = Signal()
+        m.d.sync     += past_clk.eq(serial_clock)
+        leading_edge  = ~past_clk &  serial_clock
+        trailing_edge =  past_clk & ~serial_clock
 
         # Determine the sample and output edges based on the SPI clock phase.
         sample_edge = trailing_edge if self.clock_phase else leading_edge
@@ -336,7 +337,10 @@ def elaborate(self, platform):
         m = Module()
         spi = self.spi
 
-        sample_edge = Fell(spi.sck, domain="sync")
+        # Detect falling edge of SPI clock
+        past_sck    = Signal()
+        m.d.sync   += past_sck.eq(spi.sck)
+        sample_edge = past_sck & ~spi.sck
 
         # Bit counter: counts the number of bits received.
         max_bit_count = max(self.word_size, self.command_size)
diff --git a/luna/gateware/interface/ulpi.py b/luna/gateware/interface/ulpi.py
index e3cb30c09..d4da0be66 100644
--- a/luna/gateware/interface/ulpi.py
+++ b/luna/gateware/interface/ulpi.py
@@ -11,7 +11,6 @@
 
 from amaranth       import Signal, Module, Cat, Elaboratable, ClockSignal, \
                            Record, ResetSignal, Const
-from amaranth.hdl.ast import Rose, Fell, Past
 from amaranth.hdl.rec import Record, DIR_FANIN, DIR_FANOUT, DIR_NONE
 
 from ..utils.io     import delay
@@ -1296,7 +1295,9 @@ def elaborate(self, platform):
         # A transmission starts when DIR goes high with NXT, or when an RxEvent indicates
         # a switch from RxActive = 0 to RxActive = 1. A transmission stops when DIR drops low,
         # or when the RxEvent RxActive bit drops from 1 to 0, or an error occurs.A
-        dir_rising_edge = Rose(self.ulpi.dir.i, domain="usb")
+        past_dir        = Signal.like(self.ulpi.dir.i)
+        m.d.usb        += past_dir.eq(self.ulpi.dir.i)
+        dir_rising_edge = ~past_dir & self.ulpi.dir.i
         dir_based_start = dir_rising_edge & self.ulpi.nxt
 
 
diff --git a/luna/gateware/usb/usb2/endpoint.py b/luna/gateware/usb/usb2/endpoint.py
index c7143d53d..d2d0ddddf 100644
--- a/luna/gateware/usb/usb2/endpoint.py
+++ b/luna/gateware/usb/usb2/endpoint.py
@@ -9,8 +9,7 @@
 import functools
 import operator
 
-from amaranth         import Signal, Elaboratable, Module
-from amaranth.hdl.ast import Past
+from amaranth         import Signal, Elaboratable, Module, Cat
 
 from .packet          import DataCRCInterface, InterpacketTimerInterface, TokenDetectorInterface
 from .packet          import HandshakeExchangeInterface
@@ -264,8 +263,10 @@ def elaborate(self, platform):
         conditional = m.If
 
         # We'll connect our PID toggle to whichever interface has a valid transmission going.
-        for interface in self._interfaces:
-            with conditional(interface.tx.valid | Past(interface.tx.valid, domain="usb")):
+        past_valid = Signal(len(self._interfaces))
+        m.d.usb    += past_valid.eq(Cat(interface.tx.valid for interface in self._interfaces))
+        for i, interface in enumerate(self._interfaces):
+            with conditional(interface.tx.valid | past_valid[i]):
                 m.d.comb += shared.tx_pid_toggle.eq(interface.tx_pid_toggle)
 
             conditional = m.Elif
diff --git a/luna/gateware/usb/usb3/link/command.py b/luna/gateware/usb/usb3/link/command.py
index b94daf9e8..a3e3b4275 100644
--- a/luna/gateware/usb/usb3/link/command.py
+++ b/luna/gateware/usb/usb3/link/command.py
@@ -11,7 +11,6 @@
 from enum import IntEnum
 
 from amaranth          import *
-from amaranth.hdl.ast  import Past
 
 from .crc              import compute_usb_crc5
 from ..physical.coding import SLC, EPF, stream_matches_symbols, get_word_for_symbols
diff --git a/luna/gateware/usb/usb3/link/idle.py b/luna/gateware/usb/usb3/link/idle.py
index 598ab6770..1a35debd5 100644
--- a/luna/gateware/usb/usb3/link/idle.py
+++ b/luna/gateware/usb/usb3/link/idle.py
@@ -6,7 +6,6 @@
 """ Logical idle detection / polling gateware. """
 
 from amaranth         import *
-from amaranth.hdl.ast import Past
 
 from ...stream        import USBRawSuperSpeedStream
 
@@ -57,8 +56,12 @@ def elaborate(self, platform):
         ctrl_word = self.sink.ctrl
 
         # Capture the previous data word; so we have a record of eight consecutive signals.
-        last_word = Past(self.sink.data)
-        last_ctrl = Past(self.sink.ctrl)
+        last_word = Signal.like(data_word)
+        last_ctrl = Signal.like(ctrl_word)
+        m.d.ss += [
+            last_word.eq(data_word),
+            last_ctrl.eq(ctrl_word),
+        ]
 
         # Logical idle descrambles to the raw data value zero; so we only need to validate that
         # the last and current words are both zeroes.
diff --git a/luna/gateware/usb/usb3/link/receiver.py b/luna/gateware/usb/usb3/link/receiver.py
index cebf8ca1e..912d0e0dc 100644
--- a/luna/gateware/usb/usb3/link/receiver.py
+++ b/luna/gateware/usb/usb3/link/receiver.py
@@ -8,7 +8,6 @@
 import unittest
 
 from amaranth                      import *
-from amaranth.hdl.ast              import Fell
 
 from usb_protocol.types.superspeed import LinkCommand
 
@@ -425,6 +424,9 @@ def elaborate(self, platform):
         with m.If(self.acknowledge_power_state):
             m.d.ss += lpma_pending.eq(1)
 
+        # Keep track of the last value of the enable signal
+        last_enable = Signal()
+        m.d.ss     += last_enable.eq(self.enable)
 
         #
         # Header Packet Buffers
@@ -600,7 +602,7 @@ def elaborate(self, platform):
 
                 # Once we've become disabled, we'll want to prepare for our next enable.
                 # This means preparing for our advertisement, by:
-                with m.If(Fell(self.enable) | self.usb_reset):
+                with m.If((last_enable & ~self.enable) | self.usb_reset):
                     m.d.ss += [
                         # -Resetting our pending ACKs to 1, so we perform an sequence number advertisement
                         #  when we're next enabled.
diff --git a/luna/gateware/usb/usb3/physical/alignment.py b/luna/gateware/usb/usb3/physical/alignment.py
index 0a9d181e9..d31928436 100644
--- a/luna/gateware/usb/usb3/physical/alignment.py
+++ b/luna/gateware/usb/usb3/physical/alignment.py
@@ -9,7 +9,6 @@
 """ Code for USB3 physical-layer encoding. """
 
 from amaranth import *
-from amaranth.hdl.ast import Past
 
 from .coding   import COM, SHP, SLC, EPF, get_word_for_symbols
 from ...stream import USBRawSuperSpeedStream
diff --git a/luna/gateware/usb/usb3/physical/power.py b/luna/gateware/usb/usb3/physical/power.py
index 2ff0041a8..d5694b6d8 100644
--- a/luna/gateware/usb/usb3/physical/power.py
+++ b/luna/gateware/usb/usb3/physical/power.py
@@ -9,7 +9,6 @@
 
 from amaranth import *
 from amaranth.lib.cdc import PulseSynchronizer, FFSynchronizer
-from amaranth.hdl.ast import Rose
 
 
 class PHYResetController(Elaboratable):
@@ -156,6 +155,10 @@ def elaborate(self, platform):
         # after a detection completes.
         PARTNER_PRESENT_STATUS = 0b011
 
+        # Keep track of the previous value of the request detection strobe
+        past_request_detection = Signal()
+        m.d.ss                += past_request_detection.eq(self.request_detection)
+
         with m.FSM(domain="ss"):
 
             # IDLE_P2 -- our post-startup state; represents when we're IDLE but in P2.
@@ -211,7 +214,8 @@ def elaborate(self, platform):
 
                 # We can only perform detections from P2; so, when the user requests a detection, we'll
                 # need to move back to P2.
-                with m.If(Rose(self.request_detection)):
+                request_detection_rose = ~past_request_detection & self.request_detection
+                with m.If(request_detection_rose):
                     m.next = "MOVE_TO_P2"