diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 9e339de3..00319f47 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -10,6 +10,10 @@ on:
   # Manual Dispatch
   workflow_dispatch:
 
+concurrency:
+  group: lambdalib-${{ github.workflow }}-${{ github.event.pull_request.number || github.ref }}
+  cancel-in-progress: true
+
 jobs:
   lint_python:
     name: Lint Python Code
@@ -23,9 +27,24 @@ jobs:
           . .venv/bin/activate
 
           pip install --upgrade pip
-          pip install .[dev]
+          pip install .[lint]
           flake8 --statistics .
 
+  check_spelling:
+    name: Check code spelling
+    runs-on: ubuntu-latest
+    steps:
+      - name: Check out Git repository
+        uses: actions/checkout@v6
+      - name: Check spelling with codespell
+        run: |
+          python3 -m venv .venv
+          . .venv/bin/activate
+
+          pip install --upgrade pip
+          pip install .[lint]
+          codespell .
+
   python_ci:
     name: Run Python Only
     runs-on: ubuntu-latest
@@ -38,13 +57,13 @@ jobs:
           . .venv/bin/activate
 
           pip install --upgrade pip
-          pip install .[dev]
+          pip install .[test]
 
           # change running directory
           mkdir testrun
           cd testrun
 
-          pytest $GITHUB_WORKSPACE -m "not eda"
+          pytest $GITHUB_WORKSPACE -n logical -m "not eda"
 
   lint_verilog:
     name: Lint Verilog Code
@@ -89,7 +108,7 @@ jobs:
           . .venv/bin/activate
 
           pip install --upgrade pip
-          pip install -e .[dev]
+          pip install -e .[test]
 
           # change running directory
           mkdir testrun
diff --git a/lambdalib/analoglib/la_pll/rtl/la_pll.v b/lambdalib/analoglib/la_pll/rtl/la_pll.v
index 26f4270c..8cbdf7d6 100644
--- a/lambdalib/analoglib/la_pll/rtl/la_pll.v
+++ b/lambdalib/analoglib/la_pll/rtl/la_pll.v
@@ -5,7 +5,7 @@
  *
  * NOTE: The generic interface was derived by reviewing a number of
  * publicly open source PLLs and FPGA IP datasheets and via llm
- * promting.
+ * prompting.
  *
  * This is a synthesizable zeroth order PLL model that only
  * supports one operating mode: clkout=clkref.
@@ -19,7 +19,7 @@
 module la_pll  #(parameter PROP = "",   // cell property
                  parameter NIN = 1,     // number of input reference clocks
                  parameter NOUT = 1,    // number of output clocks
-                 parameter DIVINW = 8,  // iunpyt divider width
+                 parameter DIVINW = 8,  // input divider width
                  parameter DIVFBW = 8,  // feedback divider width
                  parameter DIVOUTW = 8, // output divider width
                  parameter PHASEW = 8,  // phase shift adjust width
@@ -38,7 +38,7 @@ module la_pll  #(parameter PROP = "",   // cell property
     // standard controls
     input                    reset,  // active high async reset
     input                    en,     // pll enable
-    input                    bypass, // pll bypasses
+    input                    bypass, // pll bypass
     input [NIN-1:0]          clksel, // one hot clock selector
     input [DIVINW-1:0]       divin,  // reference divider
     input [DIVFBW-1:0]       divfb,  // feedback divider
diff --git a/lambdalib/fpgalib/la_clb4p0/rtl/la_clb4p0.v b/lambdalib/fpgalib/la_clb4p0/rtl/la_clb4p0.v
index b997f3a2..38c4850b 100644
--- a/lambdalib/fpgalib/la_clb4p0/rtl/la_clb4p0.v
+++ b/lambdalib/fpgalib/la_clb4p0/rtl/la_clb4p0.v
@@ -81,7 +81,7 @@ module la_clb4p0
           if (N>1)
             assign fbmux[i][j] = fb[i][cfgfb[(i*K+j)*$clog2(N)+:$clog2(N)]];
           else
-            assign fbmux[i][j] = fb[i][0]; //TODO: suport N=1
+            assign fbmux[i][j] = fb[i][0]; //TODO: support N=1
      end
 
    // select between feedback and primary inputs
diff --git a/pyproject.toml b/pyproject.toml
index 77a01eeb..34bcd886 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -28,8 +28,7 @@ version = {attr = "lambdalib.__version__"}
 
 [project.optional-dependencies]
 # Dev dependencies.
-dev = [
-    "flake8 == 7.3.0",
+test = [
     "pytest == 8.4.2",
     "pytest-xdist==3.8.0",
     "pytest-timeout == 2.4.0",
@@ -37,6 +36,11 @@ dev = [
     "cocotb-bus == 0.3.0"
 ]
 
+lint = [
+    "flake8 == 7.3.0",
+    "codespell == 2.4.1"
+]
+
 [tool.pytest.ini_options]
 markers = [
     "eda: this test requires EDA tools installed to run.",
@@ -48,3 +52,8 @@ testpaths = [
     "tests"
 ]
 timeout = "60"
+
+[tool.codespell]
+count = true
+quiet-level = 3
+ignore-words-list = 'inout,inouts,nin,te,dout'