diff --git a/.github/synthesis/all.json b/.github/synthesis/all.json
index 50dba47bb..bb6a283b3 100644
--- a/.github/synthesis/all.json
+++ b/.github/synthesis/all.json
@@ -17,6 +17,6 @@
   {"top": "switchCalendar1kReducedPins",   "stage": "netlist"},
 
   {"top": "extendedHardwareInTheLoopTest", "stage": "test",   "targets": "All"          },
-  {"top": "fdecTest",                      "stage": "test",   "targets": "Specific [-1]"},
+  {"top": "fincFdecTests",                 "stage": "test",   "targets": "Specific [-1]"},
   {"top": "simpleHardwareInTheLoopTest",   "stage": "test",   "targets": "All"          }
 ]
diff --git a/.github/synthesis/staging.json b/.github/synthesis/staging.json
index 5312e034e..22278834e 100644
--- a/.github/synthesis/staging.json
+++ b/.github/synthesis/staging.json
@@ -1,6 +1,6 @@
 [
   {"top": "clockControlDemo0",             "stage": "bitstream"},
   {"top": "extendedHardwareInTheLoopTest", "stage": "test", "targets": "All"},
-  {"top": "fdecTest",                      "stage": "test", "targets": "Specific [-1]"},
+  {"top": "fincFdecTests",                 "stage": "test", "targets": "Specific [-1]"},
   {"top": "simpleHardwareInTheLoopTest",   "stage": "test", "targets": "All"}
 ]
diff --git a/bittide-extra/bittide-extra.cabal b/bittide-extra/bittide-extra.cabal
index 3e12762ec..53e2a493a 100644
--- a/bittide-extra/bittide-extra.cabal
+++ b/bittide-extra/bittide-extra.cabal
@@ -75,6 +75,8 @@ library
   exposed-modules:
     Bittide.Extra.Maybe
     Bittide.Extra.Wishbone
+    Clash.Reset.Extra
+    Clash.Sized.Vector.Extra
 
 test-suite doctests
   type:             exitcode-stdio-1.0
diff --git a/bittide-extra/src/Clash/Reset/Extra.hs b/bittide-extra/src/Clash/Reset/Extra.hs
new file mode 100644
index 000000000..63d76a8af
--- /dev/null
+++ b/bittide-extra/src/Clash/Reset/Extra.hs
@@ -0,0 +1,18 @@
+-- SPDX-FileCopyrightText: 2022-2023 Google LLC
+--
+-- SPDX-License-Identifier: Apache-2.0
+
+module Clash.Reset.Extra where
+
+import Clash.Explicit.Prelude
+
+noReset :: KnownDomain dom => Reset dom
+noReset = unsafeFromHighPolarity (pure False)
+
+orReset :: KnownDomain dom => Reset dom -> Reset dom -> Reset dom
+orReset (unsafeToHighPolarity -> rstA) (unsafeToHighPolarity -> rstB) =
+  unsafeFromHighPolarity (rstA .||. rstB)
+
+andReset :: KnownDomain dom => Reset dom -> Reset dom -> Reset dom
+andReset (unsafeToHighPolarity -> rstA) (unsafeToHighPolarity -> rstB) =
+  unsafeFromHighPolarity (rstA .&&. rstB)
diff --git a/bittide-extra/src/Clash/Sized/Vector/Extra.hs b/bittide-extra/src/Clash/Sized/Vector/Extra.hs
new file mode 100644
index 000000000..b505b83c5
--- /dev/null
+++ b/bittide-extra/src/Clash/Sized/Vector/Extra.hs
@@ -0,0 +1,18 @@
+-- SPDX-FileCopyrightText: 2022-2023 Google LLC
+--
+-- SPDX-License-Identifier: Apache-2.0
+
+module Clash.Sized.Vector.Extra where
+
+import Clash.Explicit.Prelude
+import Data.Maybe (fromMaybe)
+
+find :: KnownNat n => (a -> Bool) -> Vec n a -> Maybe a
+find f = foldl (<|>) Nothing . map go
+ where
+  go a
+    | f a = Just a
+    | otherwise = Nothing
+
+findWithDefault :: KnownNat n => a -> (a -> Bool) -> Vec n a -> a
+findWithDefault a f = fromMaybe a . find f
diff --git a/bittide-instances/bin/Shake.hs b/bittide-instances/bin/Shake.hs
index 621c912d1..9d369edc2 100644
--- a/bittide-instances/bin/Shake.hs
+++ b/bittide-instances/bin/Shake.hs
@@ -239,7 +239,7 @@ targets = map enforceValidTarget
 
   , testTarget 'BoardTest.extendedHardwareInTheLoopTest
   , testTarget 'BoardTest.simpleHardwareInTheLoopTest
-  , testTarget 'FincFdec.fdecTest
+  , testTarget 'FincFdec.fincFdecTests
   ]
 
 shakeOpts :: ShakeOptions
diff --git a/bittide-instances/data/constraints/fdecTest.xdc b/bittide-instances/data/constraints/fincFdecTests.xdc
similarity index 100%
rename from bittide-instances/data/constraints/fdecTest.xdc
rename to bittide-instances/data/constraints/fincFdecTests.xdc
diff --git a/bittide-instances/src/Bittide/Instances/Tests/FincFdec.hs b/bittide-instances/src/Bittide/Instances/Tests/FincFdec.hs
index 6e3bdef19..510d80d7e 100644
--- a/bittide-instances/src/Bittide/Instances/Tests/FincFdec.hs
+++ b/bittide-instances/src/Bittide/Instances/Tests/FincFdec.hs
@@ -12,6 +12,9 @@ import Clash.Annotations.TH (makeTopEntity)
 import Clash.Explicit.Prelude
 import Clash.Prelude (withClockResetEnable)
 
+import Clash.Reset.Extra (orReset, noReset)
+import Clash.Sized.Vector.Extra (findWithDefault)
+
 import Bittide.Arithmetic.Time
 import Bittide.Counter (domainDiffCounter)
 import Bittide.ClockControl (SpeedChange(NoChange, SlowDown, SpeedUp), speedChangeToFincFdec)
@@ -27,7 +30,10 @@ import Clash.Cores.Xilinx.Xpm.Cdc.Single (xpmCdcSingle)
 import qualified Bittide.ClockControl.Si5395J as Si5395J
 
 data TestState = Busy | Fail | Success
-data Test = Fdec | Finc
+data Test = FDec | FInc | FDecInc | FIncDec deriving (Enum, Generic, NFDataX)
+
+allTests :: Vec 4 Test
+allTests = FDec :> FInc :> FDecInc :> FIncDec :> Nil
 
 testStateToDoneSuccess :: TestState -> (Bool, Bool)
 testStateToDoneSuccess = \case
@@ -35,18 +41,7 @@ testStateToDoneSuccess = \case
   Fail -> (True, False)
   Success -> (True, True)
 
-noReset :: KnownDomain dom => Reset dom
-noReset = unsafeFromHighPolarity (pure False)
-
-eitherReset :: KnownDomain dom => Reset dom -> Reset dom -> Reset dom
-eitherReset (unsafeToHighPolarity -> rstA) (unsafeToHighPolarity -> rstB) =
-  unsafeFromHighPolarity (rstA .||. rstB)
-
-bothReset :: KnownDomain dom => Reset dom -> Reset dom -> Reset dom
-bothReset (unsafeToHighPolarity -> rstA) (unsafeToHighPolarity -> rstB) =
-  unsafeFromHighPolarity (rstA .&&. rstB)
-
-fdecTestGo ::
+goFincFdecTests ::
   Clock Basic200A ->
   Reset Basic200A ->
   Clock Basic200B ->
@@ -76,7 +71,7 @@ fdecTestGo ::
       , "COUNTER" ::: Signal Basic200A (Signed 32)
       )
     )
-fdecTestGo clk rst clkControlled testSelect miso =
+goFincFdecTests clk rst clkControlled testSelect miso =
   (testResult, fIncDec, spiOut, debugSignals)
  where
   debugSignals = (spiBusy, pack <$> spiState, siClkLocked, counterActive, counter)
@@ -85,8 +80,7 @@ fdecTestGo clk rst clkControlled testSelect miso =
     withClockResetEnable clk rst enableGen $
       si539xSpi
         Si5395J.testConfig6_200_on_0a_and_0
-        -- Si5395J.testConfigAll200
-        (SNat @(Nanoseconds 1000))
+        (SNat @(Microseconds 1))
         (pure Nothing)
         miso
 
@@ -109,27 +103,57 @@ fdecTestGo clk rst clkControlled testSelect miso =
 
   fIncDec = unbundle $ speedChangeToFincFdec clk rstTest fIncDecRequest
 
-  (fIncDecRequest, testResult) =
-    mealyB clk rstTest enableGen go () (counter, testSelect)
-
-  go :: () -> (Signed 32, Test) -> ((), (SpeedChange, TestState))
-  go () (n, Fdec) = ((), goFdec n)
-  go () (n, Finc) = ((), goFinc n)
-
-
-goFdec :: Signed 32 -> (SpeedChange, TestState)
-goFdec n
-  | n > 20_000  = (NoChange, Fail)
-  | n < -20_000 = (NoChange, Success)
-  | otherwise   = (SlowDown, Busy)
-
-goFinc :: Signed 32 -> (SpeedChange, TestState)
-goFinc n
-  | n > 20_000  = (NoChange, Success)
-  | n < -20_000 = (NoChange, Fail)
-  | otherwise   = (SpeedUp, Busy)
-
-fdecTest ::
+  (fIncDecRequest, testResult) = unbundle $
+    (!!)
+      <$> bundle (fDecResult :> fIncResult :> fDecIncResult :> fIncDecResult :> Nil)
+      <*> fmap fromEnum testSelect
+
+  fDecResult = goFdec <$> counter
+  fIncResult = goFinc <$> counter
+  fDecIncResult = mealy clk rstTest enableGen goFdecFinc FDec counter
+  fIncDecResult = mealy clk rstTest enableGen goFincFdec FInc counter
+
+  -- Keep pressing FDEC, expect counter to go below -20_000
+  goFdec :: Signed 32 -> (SpeedChange, TestState)
+  goFdec n
+    | n > 20_000  = (NoChange, Fail)
+    | n < -20_000 = (NoChange, Success)
+    | otherwise   = (SlowDown, Busy)
+
+  -- Keep pressing FINC, expect counter to go above 20_000
+  goFinc :: Signed 32 -> (SpeedChange, TestState)
+  goFinc n
+    | n > 20_000  = (NoChange, Success)
+    | n < -20_000 = (NoChange, Fail)
+    | otherwise   = (SpeedUp, Busy)
+
+  -- Keep pressing FDEC, expect counter to go below -20_000, then keep pressing
+  -- FINC, expect counter to go above 0.
+  goFdecFinc :: Test -> Signed 32 -> (Test, (SpeedChange, TestState))
+  goFdecFinc FDec n
+    | n > 20_000  = (FDec, (NoChange, Fail))
+    | n < -20_000 = (FInc, (NoChange, Busy))
+    | otherwise   = (FDec, (SlowDown, Busy))
+  goFdecFinc FInc n
+    | n > 0       = (FInc, (NoChange, Success))
+    | n < -60_000 = (FInc, (NoChange, Fail))
+    | otherwise   = (FInc, (SpeedUp, Busy))
+  goFdecFinc s _ = (s, (NoChange, Fail)) -- Illegal state
+
+  -- Keep pressing FINC, expect counter to go above 20_000, then keep pressing
+  -- FDEC, expect counter to go below 0.
+  goFincFdec :: Test -> Signed 32 -> (Test, (SpeedChange, TestState))
+  goFincFdec FInc n
+    | n > 20_000  = (FDec, (NoChange, Busy))
+    | n < -20_000 = (FInc, (NoChange, Fail))
+    | otherwise   = (FInc, (SpeedUp, Busy))
+  goFincFdec FDec n
+    | n > 60_000  = (FDec, (NoChange, Fail))
+    | n < 0       = (FDec, (NoChange, Success))
+    | otherwise   = (FDec, (SlowDown, Busy))
+  goFincFdec s _ = (s, (NoChange, Fail)) -- Illegal state
+
+fincFdecTests ::
   -- Pins from internal oscillator:
   "CLK_125MHZ_P" ::: Clock Basic125 ->
   "CLK_125MHZ_N" ::: Clock Basic125 ->
@@ -158,7 +182,7 @@ fdecTest ::
       , "CSB"  ::: Signal Basic200A Bool
       )
     )
-fdecTest clkP clkN controlledClockP controlledClockN spiIn =
+fincFdecTests clkP clkN controlledClockP controlledClockN spiIn =
   ((testDone, testSuccess), fIncDec, spiOut)
  where
   clkControlled = ibufds controlledClockP controlledClockN
@@ -167,23 +191,23 @@ fdecTest clkP clkN controlledClockP controlledClockN spiIn =
   clkStable1 = xpmCdcSingle clk clk clkStable0 -- improvised reset syncer
 
   clkStableRst = unsafeFromLowPolarity clkStable1
-  startFdecTestRst = unsafeFromLowPolarity startFdecTest
-  startFincTestRst = unsafeFromLowPolarity startFincTest
-  testRst = eitherReset clkStableRst (bothReset startFdecTestRst startFincTestRst)
+  anyStarted = fold (||) <$> startTests
+  testRst = orReset clkStableRst (unsafeFromLowPolarity anyStarted)
   testRstBool = unsafeToHighPolarity testRst
 
   (fInc, fDec) = fIncDec
 
-  testF = mux startFdecTest (pure Fdec) (pure Finc)
+  testF = fst . findWithDefault (FDec, True) snd . zip allTests <$> startTests
 
   (testResult, fIncDec, spiOut, debugSignals) =
-    fdecTestGo clk testRst clkControlled testF spiIn
+    goFincFdecTests clk testRst clkControlled testF spiIn
 
   (testDone, testSuccess) = unbundle $ testStateToDoneSuccess <$> testResult
 
   (spiBusy, spiState, siClkLocked, counterActive, counter) = debugSignals
 
-  (startFdecTest, startFincTest) = unbundle $
+  startTests :: Signal Basic200A (Vec 4 Bool)
+  startTests =
     vioProbe
       (  "probe_test_done"
       :> "probe_test_success"
@@ -199,8 +223,12 @@ fdecTest clkP clkN controlledClockP controlledClockN spiIn =
       :> "probe_fInc"
       :> "probe_fDec"
       :> Nil)
-      ("probe_test_start_fdec" :> "probe_test_start_finc" :> Nil)
-      (False, False)
+      (  "probe_test_start_fdec"
+      :> "probe_test_start_finc"
+      :> "probe_test_start_fdecfinc"
+      :> "probe_test_start_fincfdec"
+      :> Nil)
+      (repeat False)
       clk
       testDone
       testSuccess
@@ -215,5 +243,5 @@ fdecTest clkP clkN controlledClockP controlledClockN spiIn =
       counter
       fInc
       fDec
-{-# NOINLINE fdecTest #-}
-makeTopEntity 'fdecTest
+{-# NOINLINE fincFdecTests #-}
+makeTopEntity 'fincFdecTests