diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index 10b9f39..5b13285 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -18,7 +18,7 @@ jobs:
       - id: boards
         run: echo "::set-output name=board_matrix::$(ls ./boards --indicator-style=none | jq -ncR '[inputs]')"
       - id: features
-        run: echo "::set-output name=feature_matrix::[\"reconfigurable-system-pins\",\"usart-spi-host-without-select\"]"
+        run: echo "::set-output name=feature_matrix::[\"reconfigurable-system-pins\",\"usart-spi-host-without-select\",\"rt\"]"
     outputs:
       pac_matrix: ${{ steps.pacs.outputs.pac_matrix }}
       board_matrix: ${{ steps.boards.outputs.board_matrix }}
@@ -111,7 +111,7 @@ jobs:
       - name: Install Clippy
         run: rustup component add clippy
       - name: Lint HAL
-        run: cargo clippy --package atsamx7x-hal --no-deps --features samv71q21b,unproven,reconfigurable-system-pins -- --deny warnings
+        run: cargo clippy --package atsamx7x-hal --no-deps --features samv71q21b,unproven,reconfigurable-system-pins,rt -- --deny warnings
 
   clippy-examples:
     if: github.event.pull_request.head.repo.full_name != github.repository
@@ -146,8 +146,6 @@ jobs:
       - name: Install Rust (thumbv7em)
         run: rustup target add thumbv7em-none-eabihf
       - name: Build HAL documentation
-        run: cargo doc --package atsamx7x-hal --no-deps --features samv71q21b,unproven,reconfigurable-system-pins
+        run: cargo doc --package atsamx7x-hal --no-deps --features samv71q21b,unproven,reconfigurable-system-pins,rt
       - name: Build HAL doc tests
-        run: cargo test --package atsamx7x-hal --doc --features samv71q21b,unproven --target x86_64-unknown-linux-gnu
-
-
+        run: cargo test --package atsamx7x-hal --doc --features samv71q21b,unproven,rt --target x86_64-unknown-linux-gnu
diff --git a/Cargo.toml b/Cargo.toml
index 21f7aaf..2baf7a8 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -9,3 +9,37 @@ exclude = [
     "pac/templates"
 ]
 
+[patch.crates-io]
+atsame70j19b = { path = "../atsamx7x-pac/pac/atsame70j19b" }
+atsame70j20b = { path = "../atsamx7x-pac/pac/atsame70j20b" }
+atsame70j21b = { path = "../atsamx7x-pac/pac/atsame70j21b" }
+atsame70n19b = { path = "../atsamx7x-pac/pac/atsame70n19b" }
+atsame70n20b = { path = "../atsamx7x-pac/pac/atsame70n20b" }
+atsame70n21b = { path = "../atsamx7x-pac/pac/atsame70n21b" }
+atsame70q19b = { path = "../atsamx7x-pac/pac/atsame70q19b" }
+atsame70q20b = { path = "../atsamx7x-pac/pac/atsame70q20b" }
+atsame70q21b = { path = "../atsamx7x-pac/pac/atsame70q21b" }
+atsams70j19b = { path = "../atsamx7x-pac/pac/atsams70j19b" }
+atsams70j20b = { path = "../atsamx7x-pac/pac/atsams70j20b" }
+atsams70j21b = { path = "../atsamx7x-pac/pac/atsams70j21b" }
+atsams70n19b = { path = "../atsamx7x-pac/pac/atsams70n19b" }
+atsams70n20b = { path = "../atsamx7x-pac/pac/atsams70n20b" }
+atsams70n21b = { path = "../atsamx7x-pac/pac/atsams70n21b" }
+atsams70q19b = { path = "../atsamx7x-pac/pac/atsams70q19b" }
+atsams70q20b = { path = "../atsamx7x-pac/pac/atsams70q20b" }
+atsams70q21b = { path = "../atsamx7x-pac/pac/atsams70q21b" }
+atsamv70j19b = { path = "../atsamx7x-pac/pac/atsamv70j19b" }
+atsamv70j20b = { path = "../atsamx7x-pac/pac/atsamv70j20b" }
+atsamv70n19b = { path = "../atsamx7x-pac/pac/atsamv70n19b" }
+atsamv70n20b = { path = "../atsamx7x-pac/pac/atsamv70n20b" }
+atsamv70q19b = { path = "../atsamx7x-pac/pac/atsamv70q19b" }
+atsamv70q20b = { path = "../atsamx7x-pac/pac/atsamv70q20b" }
+atsamv71j19b = { path = "../atsamx7x-pac/pac/atsamv71j19b" }
+atsamv71j20b = { path = "../atsamx7x-pac/pac/atsamv71j20b" }
+atsamv71j21b = { path = "../atsamx7x-pac/pac/atsamv71j21b" }
+atsamv71n19b = { path = "../atsamx7x-pac/pac/atsamv71n19b" }
+atsamv71n20b = { path = "../atsamx7x-pac/pac/atsamv71n20b" }
+atsamv71n21b = { path = "../atsamx7x-pac/pac/atsamv71n21b" }
+atsamv71q19b = { path = "../atsamx7x-pac/pac/atsamv71q19b" }
+atsamv71q20b = { path = "../atsamx7x-pac/pac/atsamv71q20b" }
+atsamv71q21b = { path = "../atsamx7x-pac/pac/atsamv71q21b" }
diff --git a/hal/Cargo.toml b/hal/Cargo.toml
index a6af242..06810a5 100644
--- a/hal/Cargo.toml
+++ b/hal/Cargo.toml
@@ -28,7 +28,7 @@ edition = "2021"
 rust-version = "1.70"
 
 [dependencies]
-cortex-m = "0.7"
+cortex-m = { version = "0.7" }
 embedded-hal = { version = "0.2.7" }
 nb = "1"
 fugit = "0.3.6"
@@ -40,39 +40,39 @@ void = { version = "1", default-features = false }
 strum = { version = "0.24.1", default-features = false, features = ["derive"]}
 cfg-if = "1"
 mcan-core = { version = "0.2", optional = true }
-atsame70j19b = { version = "0.29.0-alpha1", optional = true }
-atsame70j20b = { version = "0.29.0-alpha1", optional = true }
-atsame70j21b = { version = "0.29.0-alpha1", optional = true }
-atsame70n19b = { version = "0.29.0-alpha1", optional = true }
-atsame70n20b = { version = "0.29.0-alpha1", optional = true }
-atsame70n21b = { version = "0.29.0-alpha1", optional = true }
-atsame70q19b = { version = "0.29.0-alpha1", optional = true }
-atsame70q20b = { version = "0.29.0-alpha1", optional = true }
-atsame70q21b = { version = "0.29.0-alpha1", optional = true }
-atsams70j19b = { version = "0.29.0-alpha1", optional = true }
-atsams70j20b = { version = "0.29.0-alpha1", optional = true }
-atsams70j21b = { version = "0.29.0-alpha1", optional = true }
-atsams70n19b = { version = "0.29.0-alpha1", optional = true }
-atsams70n20b = { version = "0.29.0-alpha1", optional = true }
-atsams70n21b = { version = "0.29.0-alpha1", optional = true }
-atsams70q19b = { version = "0.29.0-alpha1", optional = true }
-atsams70q20b = { version = "0.29.0-alpha1", optional = true }
-atsams70q21b = { version = "0.29.0-alpha1", optional = true }
-atsamv70j19b = { version = "0.29.0-alpha1", optional = true }
-atsamv70j20b = { version = "0.29.0-alpha1", optional = true }
-atsamv70n19b = { version = "0.29.0-alpha1", optional = true }
-atsamv70n20b = { version = "0.29.0-alpha1", optional = true }
-atsamv70q19b = { version = "0.29.0-alpha1", optional = true }
-atsamv70q20b = { version = "0.29.0-alpha1", optional = true }
-atsamv71j19b = { version = "0.29.0-alpha1", optional = true }
-atsamv71j20b = { version = "0.29.0-alpha1", optional = true }
-atsamv71j21b = { version = "0.29.0-alpha1", optional = true }
-atsamv71n19b = { version = "0.29.0-alpha1", optional = true }
-atsamv71n20b = { version = "0.29.0-alpha1", optional = true }
-atsamv71n21b = { version = "0.29.0-alpha1", optional = true }
-atsamv71q19b = { version = "0.29.0-alpha1", optional = true }
-atsamv71q20b = { version = "0.29.0-alpha1", optional = true }
-atsamv71q21b = { version = "0.29.0-alpha1", optional = true }
+atsame70j19b = { version = "0.29.0-alpha3", optional = true, features = ["critical-section"]}
+atsame70j20b = { version = "0.29.0-alpha3", optional = true, features = ["critical-section"]}
+atsame70j21b = { version = "0.29.0-alpha3", optional = true, features = ["critical-section"]}
+atsame70n19b = { version = "0.29.0-alpha3", optional = true, features = ["critical-section"]}
+atsame70n20b = { version = "0.29.0-alpha3", optional = true, features = ["critical-section"]}
+atsame70n21b = { version = "0.29.0-alpha3", optional = true, features = ["critical-section"]}
+atsame70q19b = { version = "0.29.0-alpha3", optional = true, features = ["critical-section"]}
+atsame70q20b = { version = "0.29.0-alpha3", optional = true, features = ["critical-section"]}
+atsame70q21b = { version = "0.29.0-alpha3", optional = true, features = ["critical-section"]}
+atsams70j19b = { version = "0.29.0-alpha3", optional = true, features = ["critical-section"]}
+atsams70j20b = { version = "0.29.0-alpha3", optional = true, features = ["critical-section"]}
+atsams70j21b = { version = "0.29.0-alpha3", optional = true, features = ["critical-section"]}
+atsams70n19b = { version = "0.29.0-alpha3", optional = true, features = ["critical-section"]}
+atsams70n20b = { version = "0.29.0-alpha3", optional = true, features = ["critical-section"]}
+atsams70n21b = { version = "0.29.0-alpha3", optional = true, features = ["critical-section"]}
+atsams70q19b = { version = "0.29.0-alpha3", optional = true, features = ["critical-section"]}
+atsams70q20b = { version = "0.29.0-alpha3", optional = true, features = ["critical-section"]}
+atsams70q21b = { version = "0.29.0-alpha3", optional = true, features = ["critical-section"]}
+atsamv70j19b = { version = "0.29.0-alpha3", optional = true, features = ["critical-section"]}
+atsamv70j20b = { version = "0.29.0-alpha3", optional = true, features = ["critical-section"]}
+atsamv70n19b = { version = "0.29.0-alpha3", optional = true, features = ["critical-section"]}
+atsamv70n20b = { version = "0.29.0-alpha3", optional = true, features = ["critical-section"]}
+atsamv70q19b = { version = "0.29.0-alpha3", optional = true, features = ["critical-section"]}
+atsamv70q20b = { version = "0.29.0-alpha3", optional = true, features = ["critical-section"]}
+atsamv71j19b = { version = "0.29.0-alpha3", optional = true, features = ["critical-section"]}
+atsamv71j20b = { version = "0.29.0-alpha3", optional = true, features = ["critical-section"]}
+atsamv71j21b = { version = "0.29.0-alpha3", optional = true, features = ["critical-section"]}
+atsamv71n19b = { version = "0.29.0-alpha3", optional = true, features = ["critical-section"]}
+atsamv71n20b = { version = "0.29.0-alpha3", optional = true, features = ["critical-section"]}
+atsamv71n21b = { version = "0.29.0-alpha3", optional = true, features = ["critical-section"]}
+atsamv71q19b = { version = "0.29.0-alpha3", optional = true, features = ["critical-section"]}
+atsamv71q20b = { version = "0.29.0-alpha3", optional = true, features = ["critical-section"]}
+atsamv71q21b = { version = "0.29.0-alpha3", optional = true, features = ["critical-section"]}
 
 [patch.crates-io]
 atsame70j19b = { path = "../../atsamx7x-pac/pac/atsame70j19b" }
@@ -113,97 +113,77 @@ atsamv71q21b = { path = "../../atsamx7x-pac/pac/atsamv71q21b" }
 # Internal-only feature flags; do not set directly.
 # Refer to §2 in the data sheet.
 ## Refer to §2.
-v71 = ["can"]
-v70 = ["can"]
-e70 = ["can"]
-s70 = []
-pins-64 = []    # J variants
-pins-100 = []   # N variants
-pins-144 = []   # Q variants
-flash-2M = []   # "21"-suffix
-flash-1M = []   # "20"-suffix
-flash-512K = [] # "19"-suffix
-can = ["mcan-core"]
-
-device-selected = []
+__v71 = ["can"]
+__v70 = ["can"]
+__e70 = ["can"]
+__s70 = []
+__pins-64 = []    # J variants
+__pins-100 = []   # N variants
+__pins-144 = []   # Q variants
+__flash-2M = []   # "21"-suffix
+__flash-1M = []   # "20"-suffix
+__flash-512K = [] # "19"-suffix
+__device-selected = []
 
+# External feature flags; part of the interface.
+can = ["mcan-core"]
 unproven = ["embedded-hal/unproven"]
 usart-spi-host-without-select = []
 reconfigurable-system-pins = []
 
-same70j19b = ["atsame70j19b", "e70", "pins-64", "flash-512K", "device-selected"]
-same70j19b-rt = ["same70j19b", "atsame70j19b/rt"]
-same70j20b = ["atsame70j20b", "e70", "pins-64", "flash-1M", "device-selected"]
-same70j20b-rt = ["same70j20b", "atsame70j20b/rt"]
-same70j21b = ["atsame70j21b", "e70", "pins-64", "flash-2M", "device-selected"]
-same70j21b-rt = ["same70j21b", "atsame70j21b/rt"]
-same70n19b = ["atsame70n19b", "e70", "pins-100", "flash-512K", "device-selected"]
-same70n19b-rt = ["same70n19b", "atsame70n19b/rt"]
-same70n20b = ["atsame70n20b", "e70", "pins-100", "flash-1M", "device-selected"]
-same70n20b-rt = ["same70n20b", "atsame70n20b/rt"]
-same70n21b = ["atsame70n21b", "e70", "pins-100", "flash-2M", "device-selected"]
-same70n21b-rt = ["same70n21b", "atsame70n21b/rt"]
-same70q19b = ["atsame70q19b", "e70", "pins-144", "flash-512K", "device-selected"]
-same70q19b-rt = ["same70q19b", "atsame70q19b/rt"]
-same70q20b = ["atsame70q20b", "e70", "pins-144", "flash-1M", "device-selected"]
-same70q20b-rt = ["same70q20b", "atsame70q20b/rt"]
-same70q21b = ["atsame70q21b", "e70", "pins-144", "flash-2M", "device-selected"]
-same70q21b-rt = ["same70q21b", "atsame70q21b/rt"]
+same70j19b = ["atsame70j19b", "__e70", "__pins-64", "__flash-512K", "__device-selected"]
+same70j20b = ["atsame70j20b", "__e70", "__pins-64", "__flash-1M", "__device-selected"]
+same70j21b = ["atsame70j21b", "__e70", "__pins-64", "__flash-2M", "__device-selected"]
+same70n19b = ["atsame70n19b", "__e70", "__pins-100", "__flash-512K", "__device-selected"]
+same70n20b = ["atsame70n20b", "__e70", "__pins-100", "__flash-1M", "__device-selected"]
+same70n21b = ["atsame70n21b", "__e70", "__pins-100", "__flash-2M", "__device-selected"]
+same70q19b = ["atsame70q19b", "__e70", "__pins-144", "__flash-512K", "__device-selected"]
+same70q20b = ["atsame70q20b", "__e70", "__pins-144", "__flash-1M", "__device-selected"]
+same70q21b = ["atsame70q21b", "__e70", "__pins-144", "__flash-2M", "__device-selected"]
+
+sams70j19b = ["atsams70j19b", "__s70", "__pins-64", "__flash-512K", "__device-selected"]
+sams70j20b = ["atsams70j20b", "__s70", "__pins-64", "__flash-1M", "__device-selected"]
+sams70j21b = ["atsams70j21b", "__s70", "__pins-64", "__flash-2M", "__device-selected"]
+sams70n19b = ["atsams70n19b", "__s70", "__pins-100", "__flash-512K", "__device-selected"]
+sams70n20b = ["atsams70n20b", "__s70", "__pins-100", "__flash-1M", "__device-selected"]
+sams70n21b = ["atsams70n21b", "__s70", "__pins-100", "__flash-2M", "__device-selected"]
+sams70q19b = ["atsams70q19b", "__s70", "__pins-144", "__flash-512K", "__device-selected"]
+sams70q20b = ["atsams70q20b", "__s70", "__pins-144", "__flash-1M", "__device-selected"]
+sams70q21b = ["atsams70q21b", "__s70", "__pins-144", "__flash-2M", "__device-selected"]
+
+samv70j19b = ["atsamv70j19b", "__v70", "__pins-64", "__flash-512K", "__device-selected"]
+samv70j20b = ["atsamv70j20b", "__v70", "__pins-64", "__flash-1M", "__device-selected"]
+samv70n19b = ["atsamv70n19b", "__v70", "__pins-100", "__flash-512K", "__device-selected"]
+samv70n20b = ["atsamv70n20b", "__v70", "__pins-100", "__flash-1M", "__device-selected"]
+samv70q19b = ["atsamv70q19b", "__v70", "__pins-144", "__flash-512K", "__device-selected"]
+samv70q20b = ["atsamv70q20b", "__v70", "__pins-144", "__flash-1M", "__device-selected"]
 
-sams70j19b = ["atsams70j19b", "s70", "pins-64", "flash-512K", "device-selected"]
-sams70j19b-rt = ["sams70j19b", "atsams70j19b/rt"]
-sams70j20b = ["atsams70j20b", "s70", "pins-64", "flash-1M", "device-selected"]
-sams70j20b-rt = ["sams70j20b", "atsams70j20b/rt"]
-sams70j21b = ["atsams70j21b", "s70", "pins-64", "flash-2M", "device-selected"]
-sams70j21b-rt = ["sams70j21b", "atsams70j21b/rt"]
-sams70n19b = ["atsams70n19b", "s70", "pins-100", "flash-512K", "device-selected"]
-sams70n19b-rt = ["sams70n19b", "atsams70n19b/rt"]
-sams70n20b = ["atsams70n20b", "s70", "pins-100", "flash-1M", "device-selected"]
-sams70n20b-rt = ["sams70n20b", "atsams70n20b/rt"]
-sams70n21b = ["atsams70n21b", "s70", "pins-100", "flash-2M", "device-selected"]
-sams70n21b-rt = ["sams70n21b", "atsams70n21b/rt"]
-sams70q19b = ["atsams70q19b", "s70", "pins-144", "flash-512K", "device-selected"]
-sams70q19b-rt = ["sams70q19b", "atsams70q19b/rt"]
-sams70q20b = ["atsams70q20b", "s70", "pins-144", "flash-1M", "device-selected"]
-sams70q20b-rt = ["sams70q20b", "atsams70q20b/rt"]
-sams70q21b = ["atsams70q21b", "s70", "pins-144", "flash-2M", "device-selected"]
-sams70q21b-rt = ["sams70q21b", "atsams70q21b/rt"]
+samv71j19b = ["atsamv71j19b", "__v71", "__pins-64", "__flash-512K", "__device-selected"]
+samv71j20b = ["atsamv71j20b", "__v71", "__pins-64", "__flash-1M", "__device-selected"]
+samv71j21b = ["atsamv71j21b", "__v71", "__pins-64", "__flash-2M", "__device-selected"]
+samv71n19b = ["atsamv71n19b", "__v71", "__pins-100", "__flash-512K", "__device-selected"]
+samv71n20b = ["atsamv71n20b", "__v71", "__pins-100", "__flash-1M", "__device-selected"]
+samv71n21b = ["atsamv71n21b", "__v71", "__pins-100", "__flash-2M", "__device-selected"]
+samv71q19b = ["atsamv71q19b", "__v71", "__pins-144", "__flash-512K", "__device-selected"]
+samv71q20b = ["atsamv71q20b", "__v71", "__pins-144", "__flash-1M", "__device-selected"]
+samv71q21b = ["atsamv71q21b", "__v71", "__pins-144", "__flash-2M", "__device-selected"]
 
-samv70j19b = ["atsamv70j19b", "v70", "pins-64", "flash-512K", "device-selected"]
-samv70j19b-rt = ["samv70j19b", "atsamv70j19b/rt"]
-samv70j20b = ["atsamv70j20b", "v70", "pins-64", "flash-1M", "device-selected"]
-samv70j20b-rt = ["samv70j20b", "atsamv70j20b/rt"]
-samv70n19b = ["atsamv70n19b", "v70", "pins-100", "flash-512K", "device-selected"]
-samv70n19b-rt = ["samv70n19b", "atsamv70n19b/rt"]
-samv70n20b = ["atsamv70n20b", "v70", "pins-100", "flash-1M", "device-selected"]
-samv70n20b-rt = ["samv70n20b", "atsamv70n20b/rt"]
-samv70q19b = ["atsamv70q19b", "v70", "pins-144", "flash-512K", "device-selected"]
-samv70q19b-rt = ["samv70q19b", "atsamv70q19b/rt"]
-samv70q20b = ["atsamv70q20b", "v70", "pins-144", "flash-1M", "device-selected"]
-samv70q20b-rt = ["samv70q20b", "atsamv70q20b/rt"]
+rt = ["atsame70j19b?/rt", "atsame70j20b?/rt", "atsame70j21b?/rt",
+      "atsame70n19b?/rt", "atsame70n20b?/rt", "atsame70n21b?/rt",
+      "atsame70q19b?/rt", "atsame70q20b?/rt", "atsame70q21b?/rt",
+      "atsams70j19b?/rt", "atsams70j20b?/rt", "atsams70j21b?/rt",
+      "atsams70n19b?/rt", "atsams70n20b?/rt", "atsams70n21b?/rt",
+      "atsams70q19b?/rt", "atsams70q20b?/rt", "atsams70q21b?/rt",
+      "atsamv70j19b?/rt", "atsamv70j20b?/rt", "atsamv70n19b?/rt",
+      "atsamv70n20b?/rt", "atsamv70q19b?/rt", "atsamv70q20b?/rt",
+      "atsamv71j19b?/rt", "atsamv71j20b?/rt", "atsamv71j21b?/rt",
+      "atsamv71n19b?/rt", "atsamv71n20b?/rt", "atsamv71n21b?/rt",
+      "atsamv71q19b?/rt", "atsamv71q20b?/rt", "atsamv71q21b?/rt"]
 
-samv71j19b = ["atsamv71j19b", "v71", "pins-64", "flash-512K", "device-selected"]
-samv71j19b-rt = ["samv71j19b", "atsamv71j19b/rt"]
-samv71j20b = ["atsamv71j20b", "v71", "pins-64", "flash-1M", "device-selected"]
-samv71j20b-rt = ["samv71j20b", "atsamv71j20b/rt"]
-samv71j21b = ["atsamv71j21b", "v71", "pins-64", "flash-2M", "device-selected"]
-samv71j21b-rt = ["samv71j21b", "atsamv71j21b/rt"]
-samv71n19b = ["atsamv71n19b", "v71", "pins-100", "flash-512K", "device-selected"]
-samv71n19b-rt = ["samv71n19b", "atsamv71n19b/rt"]
-samv71n20b = ["atsamv71n20b", "v71", "pins-100", "flash-1M", "device-selected"]
-samv71n20b-rt = ["samv71n20b", "atsamv71n20b/rt"]
-samv71n21b = ["atsamv71n21b", "v71", "pins-100", "flash-2M", "device-selected"]
-samv71n21b-rt = ["samv71n21b", "atsamv71n21b/rt"]
-samv71q19b = ["atsamv71q19b", "v71", "pins-144", "flash-512K", "device-selected"]
-samv71q19b-rt = ["samv71q19b", "atsamv71q19b/rt"]
-samv71q20b = ["atsamv71q20b", "v71", "pins-144", "flash-1M", "device-selected"]
-samv71q20b-rt = ["samv71q20b", "atsamv71q20b/rt"]
-samv71q21b = ["atsamv71q21b", "v71", "pins-144", "flash-2M", "device-selected"]
-samv71q21b-rt = ["samv71q21b", "atsamv71q21b/rt"]
 
 [package.metadata.docs.rs]
 # docs.rs build target
 default-target = "thumbv7em-none-eabihf"
 
 # enable features to get maximum doc coverage
-features = ["samv71q21b-rt", "unproven", "usart-spi-host-without-select", "reconfigurable-system-pins"]
+features = ["samv71q21b", "rt", "unproven", "usart-spi-host-without-select", "reconfigurable-system-pins"]
diff --git a/hal/build.rs b/hal/build.rs
index a0428af..f0db39c 100644
--- a/hal/build.rs
+++ b/hal/build.rs
@@ -11,7 +11,7 @@ fn main() -> Result<(), &'static str> {
         .is_ok()
     }
 
-    if !feat("device-selected") || ["e70", "s70", "v70", "v71"].iter().all(|&f| !feat(f)) {
+    if !feat("__device-selected") || ["__e70", "__s70", "__v70", "__v71"].iter().all(|&f| !feat(f)) {
         return Err(
             "The HAL is built for a specific target device selected using a feature, but no such a feature was selected."
         );
diff --git a/hal/src/afec.rs b/hal/src/afec.rs
index cd398f8..f33d599 100644
--- a/hal/src/afec.rs
+++ b/hal/src/afec.rs
@@ -20,7 +20,7 @@ This implementation presumes that VREFP is 3.3V.
 # use hal::efc::*;
 # use hal::afec::*;
 # use hal::fugit::RateExtU32;
-# let pac = unsafe{ hal::pac::Peripherals::steal() };
+# let pac = hal::pac::Peripherals::take().unwrap();
 # let (slck, mut mck) = Tokens::new((pac.PMC, pac.SUPC, pac.UTMI), &pac.WDT.into()).por_state(&mut Efc::new(pac.EFC, VddioLevel::V3));
 
 let banka = BankA::new(pac.PIOA, &mut mck, &slck, BankConfiguration::default());
@@ -76,49 +76,49 @@ impl_channel_pins!(
     Afec0 {
         // Channel 11 is dedicated to the temperature sensor.
 
-        #[cfg(not(feature = "pins-64"))]
+        #[cfg(not(feature = "__pins-64"))]
         (PA17, 6),
-        #[cfg(not(feature = "pins-64"))]
+        #[cfg(not(feature = "__pins-64"))]
         (PA18, 7),
-        #[cfg(not(feature = "pins-64"))]
+        #[cfg(not(feature = "__pins-64"))]
         (PA19, 8),
-        #[cfg(not(feature = "pins-64"))]
+        #[cfg(not(feature = "__pins-64"))]
         (PA20, 9),
         (PA21, 1),
         (PB0, 10),
         (PB2, 5),
         (PB3, 2),
-        #[cfg(not(feature = "pins-64"))]
+        #[cfg(not(feature = "__pins-64"))]
         (PD30, 0),
-        #[cfg(feature = "pins-144")]
+        #[cfg(feature = "__pins-144")]
         (PE4, 4),
-        #[cfg(feature = "pins-144")]
+        #[cfg(feature = "__pins-144")]
         (PE5, 3),
     }
 
     Afec1 {
         (PB1, 0),
-        #[cfg(feature = "pins-144")]
+        #[cfg(feature = "__pins-144")]
         (PC0, 9),
-        #[cfg(feature = "pins-144")]
+        #[cfg(feature = "__pins-144")]
         (PC12, 3),
-        #[cfg(feature = "pins-144")]
+        #[cfg(feature = "__pins-144")]
         (PC13, 1),
-        #[cfg(feature = "pins-144")]
+        #[cfg(feature = "__pins-144")]
         (PC15, 2),
-        #[cfg(feature = "pins-144")]
+        #[cfg(feature = "__pins-144")]
         (PC26, 7),
-        #[cfg(feature = "pins-144")]
+        #[cfg(feature = "__pins-144")]
         (PC27, 8),
-        #[cfg(feature = "pins-144")]
+        #[cfg(feature = "__pins-144")]
         (PC29, 4),
-        #[cfg(feature = "pins-144")]
+        #[cfg(feature = "__pins-144")]
         (PC30, 5),
-        #[cfg(feature = "pins-144")]
+        #[cfg(feature = "__pins-144")]
         (PC31, 6),
-        #[cfg(feature = "pins-144")]
+        #[cfg(feature = "__pins-144")]
         (PE0, 11),
-        #[cfg(feature = "pins-144")]
+        #[cfg(feature = "__pins-144")]
         (PE3, 10),
     }
 );
diff --git a/hal/src/can.rs b/hal/src/can.rs
index 8df8a4f..ad244eb 100644
--- a/hal/src/can.rs
+++ b/hal/src/can.rs
@@ -54,10 +54,10 @@ unsafe impl mcan_core::CanId for Can0 {
 }
 
 /// Identity type for `MCAN1`
-#[cfg(any(feature = "pins-100", feature = "pins-144"))]
+#[cfg(any(feature = "__pins-100", feature = "__pins-144"))]
 pub enum Can1 {}
 
-#[cfg(any(feature = "pins-100", feature = "pins-144"))]
+#[cfg(any(feature = "__pins-100", feature = "__pins-144"))]
 impl CanMeta for Can1 {
     const PID: PeripheralIdentifier = PeripheralIdentifier::MCAN1;
     type REG = crate::pac::MCAN1;
@@ -66,10 +66,10 @@ impl CanMeta for Can1 {
     }
 }
 
-#[cfg(any(feature = "pins-100", feature = "pins-144"))]
+#[cfg(any(feature = "__pins-100", feature = "__pins-144"))]
 impl generics::Sealed for Can1 {}
 
-#[cfg(any(feature = "pins-100", feature = "pins-144"))]
+#[cfg(any(feature = "__pins-100", feature = "__pins-144"))]
 unsafe impl mcan_core::CanId for Can1 {
     const ADDRESS: *const () = <Self as CanMeta>::REG::PTR as _;
 }
@@ -159,22 +159,22 @@ impl TxPin for Pin<PB2, PeripheralA> {
     type ValidFor = Can0;
 }
 
-#[cfg(feature = "pins-144")]
+#[cfg(feature = "__pins-144")]
 impl RxPin for Pin<PC12, PeripheralC> {
     type ValidFor = Can1;
 }
 
-#[cfg(feature = "pins-100")]
+#[cfg(feature = "__pins-100")]
 impl RxPin for Pin<PD28, PeripheralB> {
     type ValidFor = Can1;
 }
 
-#[cfg(feature = "pins-144")]
+#[cfg(feature = "__pins-144")]
 impl TxPin for Pin<PC14, PeripheralC> {
     type ValidFor = Can1;
 }
 
-#[cfg(any(feature = "pins-100", feature = "pins-144"))]
+#[cfg(any(feature = "__pins-100", feature = "__pins-144"))]
 impl TxPin for Pin<PD12, PeripheralB> {
     type ValidFor = Can1;
 }
diff --git a/hal/src/clocks/mod.rs b/hal/src/clocks/mod.rs
index ea9f800..23d9cdd 100644
--- a/hal/src/clocks/mod.rs
+++ b/hal/src/clocks/mod.rs
@@ -238,7 +238,7 @@ pub enum ClockError {
     InvalidHccFreq(Megahertz),
 
     /// The V70/V71 must be driven with VDDIO = 3.3V, typical.
-    #[cfg(any(feature = "v70", feature = "v71"))]
+    #[cfg(any(feature = "__v70", feature = "__v71"))]
     InvalidVddioLevel,
 }
 
diff --git a/hal/src/efc.rs b/hal/src/efc.rs
index 74341cd..245000b 100644
--- a/hal/src/efc.rs
+++ b/hal/src/efc.rs
@@ -66,7 +66,7 @@ enum FlashWaitStates {
 
 impl FlashWaitStates {
     pub fn calculate(freq: Megahertz, vddio: &VddioLevel) -> Result<Self, ClockError> {
-        #[cfg(any(feature = "v70", feature = "v71"))]
+        #[cfg(any(feature = "__v70", feature = "__v71"))]
         if vddio == &VddioLevel::V1 {
             // V70/V71 must be driven with VDDIO = 3.3V, typical
             return Err(ClockError::InvalidVddioLevel);
diff --git a/hal/src/lib.rs b/hal/src/lib.rs
index 5c8a9be..13c837d 100644
--- a/hal/src/lib.rs
+++ b/hal/src/lib.rs
@@ -171,27 +171,27 @@ pub use atsamv71q21 as pac;
 #[cfg(feature = "samv71q21b")]
 pub use atsamv71q21b as pac;
 
-#[cfg(feature = "device-selected")]
+#[cfg(feature = "__device-selected")]
 pub mod afec;
-#[cfg(all(feature = "device-selected", feature = "can"))]
+#[cfg(all(feature = "__device-selected", feature = "can"))]
 pub mod can;
-#[cfg(feature = "device-selected")]
+#[cfg(feature = "__device-selected")]
 pub mod clocks;
-#[cfg(feature = "device-selected")]
+#[cfg(feature = "__device-selected")]
 pub mod efc;
-#[cfg(feature = "device-selected")]
+#[cfg(feature = "__device-selected")]
 pub mod generics;
-#[cfg(feature = "device-selected")]
+#[cfg(feature = "__device-selected")]
 pub mod pio;
-#[cfg(feature = "device-selected")]
+#[cfg(feature = "__device-selected")]
 pub mod pwm;
-#[cfg(feature = "device-selected")]
+#[cfg(feature = "__device-selected")]
 pub mod rtt;
-#[cfg(feature = "device-selected")]
+#[cfg(feature = "__device-selected")]
 pub mod serial;
-#[cfg(feature = "device-selected")]
+#[cfg(feature = "__device-selected")]
 pub mod tc;
-#[cfg(feature = "device-selected")]
+#[cfg(feature = "__device-selected")]
 pub mod usb;
-#[cfg(feature = "device-selected")]
+#[cfg(feature = "__device-selected")]
 pub mod watchdog;
diff --git a/hal/src/pio/bank.rs b/hal/src/pio/bank.rs
index e79e76f..42fce89 100644
--- a/hal/src/pio/bank.rs
+++ b/hal/src/pio/bank.rs
@@ -315,16 +315,16 @@ macro_rules! banks {
 
 banks!(
     A {
-        #[cfg(not(feature = "pins-64"))]
+        #[cfg(not(feature = "__pins-64"))]
         (PA0, 0),
-        #[cfg(not(feature = "pins-64"))]
+        #[cfg(not(feature = "__pins-64"))]
         (PA1, 1),
-        #[cfg(not(feature = "pins-64"))]
+        #[cfg(not(feature = "__pins-64"))]
         (PA2, 2),
         (PA3, 3),
         (PA4, 4),
         (PA5, 5),
-        #[cfg(feature = "pins-144")]
+        #[cfg(feature = "__pins-144")]
         (PA6, 6),
         (PA7, 7),
         (PA8, 8),
@@ -334,35 +334,35 @@ banks!(
         (PA12, 12),
         (PA13, 13),
         (PA14, 14),
-        #[cfg(not(feature = "pins-64"))]
+        #[cfg(not(feature = "__pins-64"))]
         (PA15, 15),
-        #[cfg(not(feature = "pins-64"))]
+        #[cfg(not(feature = "__pins-64"))]
         (PA16, 16),
-        #[cfg(not(feature = "pins-64"))]
+        #[cfg(not(feature = "__pins-64"))]
         (PA17, 17),
-        #[cfg(not(feature = "pins-64"))]
+        #[cfg(not(feature = "__pins-64"))]
         (PA18, 18),
-        #[cfg(not(feature = "pins-64"))]
+        #[cfg(not(feature = "__pins-64"))]
         (PA19, 19),
-        #[cfg(not(feature = "pins-64"))]
+        #[cfg(not(feature = "__pins-64"))]
         (PA20, 20),
         (PA21, 21),
         (PA22, 22),
-        #[cfg(not(feature = "pins-64"))]
+        #[cfg(not(feature = "__pins-64"))]
         (PA23, 23),
         (PA24, 24),
-        #[cfg(not(feature = "pins-64"))]
+        #[cfg(not(feature = "__pins-64"))]
         (PA25, 25),
-        #[cfg(not(feature = "pins-64"))]
+        #[cfg(not(feature = "__pins-64"))]
         (PA26, 26),
         (PA27, 27),
-        #[cfg(not(feature = "pins-64"))]
+        #[cfg(not(feature = "__pins-64"))]
         (PA28, 28),
-        #[cfg(feature = "pins-144")]
+        #[cfg(feature = "__pins-144")]
         (PA29, 29),
-        #[cfg(not(feature = "pins-64"))]
+        #[cfg(not(feature = "__pins-64"))]
         (PA30, 30),
-        #[cfg(not(feature = "pins-64"))]
+        #[cfg(not(feature = "__pins-64"))]
         (PA31, 31),
     }
 
@@ -383,11 +383,11 @@ banks!(
         (PB9, 9),
         #[cfg(feature = "reconfigurable-system-pins")]
         (PB12, 12),
-        #[cfg(not(feature = "pins-64"))]
+        #[cfg(not(feature = "__pins-64"))]
         (PB13, 13),
     }
 
-    #[cfg(feature = "pins-144")]
+    #[cfg(feature = "__pins-144")]
     C {
         (PC0, 0),
         (PC1, 1),
@@ -437,41 +437,41 @@ banks!(
         (PD10, 10),
         (PD11, 11),
         (PD12, 12),
-        #[cfg(not(feature = "pins-64"))]
+        #[cfg(not(feature = "__pins-64"))]
         (PD13, 13),
-        #[cfg(not(feature = "pins-64"))]
+        #[cfg(not(feature = "__pins-64"))]
         (PD14, 14),
-        #[cfg(not(feature = "pins-64"))]
+        #[cfg(not(feature = "__pins-64"))]
         (PD15, 15),
-        #[cfg(not(feature = "pins-64"))]
+        #[cfg(not(feature = "__pins-64"))]
         (PD16, 16),
-        #[cfg(not(feature = "pins-64"))]
+        #[cfg(not(feature = "__pins-64"))]
         (PD17, 17),
-        #[cfg(not(feature = "pins-64"))]
+        #[cfg(not(feature = "__pins-64"))]
         (PD18, 18),
-        #[cfg(not(feature = "pins-64"))]
+        #[cfg(not(feature = "__pins-64"))]
         (PD19, 19),
-        #[cfg(not(feature = "pins-64"))]
+        #[cfg(not(feature = "__pins-64"))]
         (PD20, 20),
         (PD21, 21),
         (PD22, 22),
-        #[cfg(feature = "pins-144")]
+        #[cfg(feature = "__pins-144")]
         (PD23, 23),
         (PD24, 24),
         (PD25, 25),
         (PD26, 26),
-        #[cfg(not(feature = "pins-64"))]
+        #[cfg(not(feature = "__pins-64"))]
         (PD27, 27),
-        #[cfg(not(feature = "pins-64"))]
+        #[cfg(not(feature = "__pins-64"))]
         (PD28, 28),
-        #[cfg(feature = "pins-144")]
+        #[cfg(feature = "__pins-144")]
         (PD29, 29),
-        #[cfg(not(feature = "pins-64"))]
+        #[cfg(not(feature = "__pins-64"))]
         (PD30, 30),
         (PD31, 31),
     }
 
-    #[cfg(feature = "pins-144")]
+    #[cfg(feature = "__pins-144")]
     E {
         (PE0, 0),
         (PE1, 1),
diff --git a/hal/src/pio/dynpin.rs b/hal/src/pio/dynpin.rs
index d0d1774..84489dc 100644
--- a/hal/src/pio/dynpin.rs
+++ b/hal/src/pio/dynpin.rs
@@ -86,10 +86,10 @@ pub enum DynPinMode {
 pub enum DynBank {
     A,
     B,
-    #[cfg(feature = "pins-144")]
+    #[cfg(feature = "__pins-144")]
     C,
     D,
-    #[cfg(feature = "pins-144")]
+    #[cfg(feature = "__pins-144")]
     E,
 }
 
@@ -98,10 +98,10 @@ impl DynBank {
         match self {
             Self::A => PIOA::ptr(),
             Self::B => PIOB::ptr(),
-            #[cfg(feature = "pins-144")]
+            #[cfg(feature = "__pins-144")]
             Self::C => PIOC::ptr(),
             Self::D => PIOD::ptr(),
-            #[cfg(feature = "pins-144")]
+            #[cfg(feature = "__pins-144")]
             Self::E => PIOE::ptr(),
         }
     }
diff --git a/hal/src/pio/mod.rs b/hal/src/pio/mod.rs
index 48ea302..43c832d 100644
--- a/hal/src/pio/mod.rs
+++ b/hal/src/pio/mod.rs
@@ -129,7 +129,7 @@ use crate::pac::{
     PIOB,
     PIOD,
 };
-#[cfg(feature = "pins-144")]
+#[cfg(feature = "__pins-144")]
 use crate::pac::{PIOC, PIOE};
 
 pub mod pin;
diff --git a/hal/src/pwm.rs b/hal/src/pwm.rs
index 8907311..8d280b6 100644
--- a/hal/src/pwm.rs
+++ b/hal/src/pwm.rs
@@ -17,7 +17,7 @@ Refer to §51 for a full description of the PWM peripheral.
 # use hal::efc::*;
 # use hal::pwm::*;
 # use hal::fugit::RateExtU32;
-# let pac = unsafe{hal::pac::Peripherals::steal()};
+# let pac = hal::pac::Peripherals::take().unwrap();
 # let (slck, mut mck) = Tokens::new((pac.PMC, pac.SUPC, pac.UTMI), &pac.WDT.into()).por_state(&mut Efc::new(pac.EFC, VddioLevel::V3));
 use hal::ehal::PwmPin;
 
@@ -441,23 +441,23 @@ impl_pwm!(
         Ch0: {
             // PWMC0_PWMH0
             H: [
-                #[cfg(not(feature = "pins-64"))]
+                #[cfg(not(feature = "__pins-64"))]
                 Pin<PA0, PeripheralA>,
                 Pin<PA11, PeripheralB>,
-                #[cfg(not(feature = "pins-64"))]
+                #[cfg(not(feature = "__pins-64"))]
                 Pin<PA23, PeripheralB>,
                 Pin<PB0, PeripheralA>,
-                #[cfg(feature = "pins-144")]
+                #[cfg(feature = "__pins-144")]
                 Pin<PC0, PeripheralB>,
                 Pin<PD11, PeripheralB>,
-                #[cfg(not(feature = "pins-64"))]
+                #[cfg(not(feature = "__pins-64"))]
                 Pin<PD20, PeripheralB>,
             ],
             // PWMC0_PWML0
             L: [
-                #[cfg(not(feature = "pins-64"))]
+                #[cfg(not(feature = "__pins-64"))]
                 Pin<PA1, PeripheralA>,
-                #[cfg(not(feature = "pins-64"))]
+                #[cfg(not(feature = "__pins-64"))]
                 Pin<PA19, PeripheralB>,
                 #[cfg(feature = "reconfigurable-system-pins")]
                 Pin<PB5, PeripheralB>,
@@ -476,7 +476,7 @@ impl_pwm!(
         Ch1: {
             // PWMC0_PWMH1
             H: [
-                #[cfg(not(feature = "pins-64"))]
+                #[cfg(not(feature = "__pins-64"))]
                 Pin<PA2, PeripheralA>,
                 Pin<PA12, PeripheralB>,
                 Pin<PA24, PeripheralB>,
@@ -485,15 +485,15 @@ impl_pwm!(
             ],
             // PWMC0_PWML1
             L: [
-                #[cfg(not(feature = "pins-64"))]
+                #[cfg(not(feature = "__pins-64"))]
                 Pin<PA20, PeripheralB>,
-                #[cfg(not(feature = "pins-64"))]
+                #[cfg(not(feature = "__pins-64"))]
                 Pin<PA30, PeripheralA>,
                 #[cfg(feature = "reconfigurable-system-pins")]
                 Pin<PB12, PeripheralA>,
-                #[cfg(feature = "pins-144")]
+                #[cfg(feature = "__pins-144")]
                 Pin<PC1, PeripheralB>,
-                #[cfg(feature = "pins-144")]
+                #[cfg(feature = "__pins-144")]
                 Pin<PC18, PeripheralB>,
                 Pin<PD25, PeripheralB>,
             ],
@@ -510,22 +510,22 @@ impl_pwm!(
             // PWMC0_PWMH2
             H: [
                 Pin<PA13, PeripheralB>,
-                #[cfg(not(feature = "pins-64"))]
+                #[cfg(not(feature = "__pins-64"))]
                 Pin<PA25, PeripheralB>,
                 #[cfg(feature = "reconfigurable-system-pins")]
                 Pin<PB4, PeripheralB>,
-                #[cfg(feature = "pins-144")]
+                #[cfg(feature = "__pins-144")]
                 Pin<PC19, PeripheralB>,
                 Pin<PD22, PeripheralB>,
             ],
             // PWMC0_PWML2
             L: [
-                #[cfg(not(feature = "pins-64"))]
+                #[cfg(not(feature = "__pins-64"))]
                 Pin<PA16, PeripheralC>,
                 Pin<PA13, PeripheralA>,
-                #[cfg(feature = "pins-144")]
+                #[cfg(feature = "__pins-144")]
                 Pin<PC2, PeripheralB>,
-                #[cfg(feature = "pins-144")]
+                #[cfg(feature = "__pins-144")]
                 Pin<PC20, PeripheralB>,
                 Pin<PD26, PeripheralB>,
             ],
@@ -541,26 +541,26 @@ impl_pwm!(
             H: [
                 Pin<PA7, PeripheralB>,
                 Pin<PA14, PeripheralB>,
-                #[cfg(not(feature = "pins-64"))]
+                #[cfg(not(feature = "__pins-64"))]
                 Pin<PA17, PeripheralC>,
-                #[cfg(feature = "pins-144")]
+                #[cfg(feature = "__pins-144")]
                 Pin<PC13, PeripheralB>,
-                #[cfg(feature = "pins-144")]
+                #[cfg(feature = "__pins-144")]
                 Pin<PC21, PeripheralB>,
-                #[cfg(feature = "pins-144")]
+                #[cfg(feature = "__pins-144")]
                 Pin<PD23, PeripheralB>,
             ],
             // PWMC0_PWML3
             L: [
-                #[cfg(not(feature = "pins-64"))]
+                #[cfg(not(feature = "__pins-64"))]
                 Pin<PA15, PeripheralC>,
-                #[cfg(feature = "pins-144")]
+                #[cfg(feature = "__pins-144")]
                 Pin<PC3, PeripheralB>,
-                #[cfg(feature = "pins-144")]
+                #[cfg(feature = "__pins-144")]
                 Pin<PC15, PeripheralB>,
-                #[cfg(feature = "pins-144")]
+                #[cfg(feature = "__pins-144")]
                 Pin<PC22, PeripheralB>,
-                #[cfg(not(feature = "pins-64"))]
+                #[cfg(not(feature = "__pins-64"))]
                 Pin<PD27, PeripheralB>,
             ],
             // PWMC0_PWMEXTRG3
@@ -614,13 +614,13 @@ impl_pwm!(
         Ch2: {
             // PWMC1_PWMH2
             H: [
-                #[cfg(not(feature = "pins-64"))]
+                #[cfg(not(feature = "__pins-64"))]
                 Pin<PA31, PeripheralD>,
                 Pin<PD5, PeripheralB>,
             ],
             // PWMC1_PWML2
             L: [
-                #[cfg(not(feature = "pins-64"))]
+                #[cfg(not(feature = "__pins-64"))]
                 Pin<PA23, PeripheralD>,
                 Pin<PD4, PeripheralB>,
             ],
diff --git a/hal/src/serial/mod.rs b/hal/src/serial/mod.rs
index 653a641..e6537ac 100644
--- a/hal/src/serial/mod.rs
+++ b/hal/src/serial/mod.rs
@@ -26,5 +26,5 @@ pub mod usart;
 pub mod twi;
 pub use twi::*;
 
-#[cfg(not(feature = "pins-64"))]
+#[cfg(not(feature = "__pins-64"))]
 pub mod spi;
diff --git a/hal/src/serial/spi.rs b/hal/src/serial/spi.rs
index 5ffcb78..a2584de 100644
--- a/hal/src/serial/spi.rs
+++ b/hal/src/serial/spi.rs
@@ -63,7 +63,7 @@ use super::Bps;
 use crate::clocks::{Clock, HostClock, PeripheralIdentifier};
 use crate::ehal::blocking;
 use crate::fugit::{ExtU32, NanosDurationU32 as NanosDuration};
-#[cfg(feature = "pins-144")]
+#[cfg(feature = "__pins-144")]
 use crate::pac::SPI1;
 use crate::pac::{spi0::tdr::PCSSELECT_AW as HwChipSelect, spi0::RegisterBlock, SPI0};
 use crate::{ehal, nb};
@@ -578,7 +578,7 @@ impl_spi!(
         ],
     },
 
-    #[cfg(feature = "pins-144")]
+    #[cfg(feature = "__pins-144")]
     Spi1: {
         MISO: [ Pin<PC26, PeripheralC> ],
         MOSI: [ Pin<PC27, PeripheralC> ],
diff --git a/hal/src/serial/twi.rs b/hal/src/serial/twi.rs
index 678b9af..c8154ec 100644
--- a/hal/src/serial/twi.rs
+++ b/hal/src/serial/twi.rs
@@ -47,7 +47,7 @@ use crate::ehal::blocking;
 use crate::generics;
 #[cfg(feature = "reconfigurable-system-pins")]
 use crate::pac::TWIHS1;
-#[cfg(not(feature = "pins-64"))]
+#[cfg(not(feature = "__pins-64"))]
 use crate::pac::TWIHS2;
 use crate::pac::{
     twihs0::{sr::R as StatusRegister, RegisterBlock},
@@ -301,7 +301,7 @@ impl_twi!(
         DATA: Pin<PB4, PeripheralA>,
         CLOCK: Pin<PB5, PeripheralA>,
     },
-    #[cfg(not(feature = "pins-64"))]
+    #[cfg(not(feature = "__pins-64"))]
     TwiHS2: {
         DATA: Pin<PD27, PeripheralC>,
         CLOCK: Pin<PD28, PeripheralC>,
diff --git a/hal/src/serial/uart.rs b/hal/src/serial/uart.rs
index ef233d9..67669a9 100644
--- a/hal/src/serial/uart.rs
+++ b/hal/src/serial/uart.rs
@@ -72,8 +72,8 @@ use crate::fugit::HertzU32 as Hertz;
 use crate::pac::uart0::mr::{CHMODESELECT_A as ChannelModeInner, PARSELECT_A as ParityModeInner};
 use crate::pac::{uart0::RegisterBlock, UART0, UART1, UART2};
 #[cfg(all(
-    any(feature = "e70", feature = "s70", feature = "v71"),
-    any(feature = "pins-100", feature = "pins-144")
+    any(feature = "__e70", feature = "__s70", feature = "__v71"),
+    any(feature = "__pins-100", feature = "__pins-144")
 ))]
 use crate::pac::{UART3, UART4};
 use crate::serial::Bps;
@@ -511,7 +511,7 @@ impl_uart!(
         RX: [ Pin<PA5, PeripheralC> ],
         TX: [
             Pin<PA4, PeripheralC>,
-            #[cfg(feature = "pins-144")]
+            #[cfg(feature = "__pins-144")]
             Pin<PA6, PeripheralC>,
             Pin<PD26, PeripheralD>,
         ],
@@ -521,16 +521,16 @@ impl_uart!(
         TX: [ Pin<PD26, PeripheralC>, ],
     },
     #[cfg(all(
-        any(feature = "e70", feature = "s70", feature = "v71"),
-        any(feature = "pins-100", feature = "pins-144")
+        any(feature = "__e70", feature = "__s70", feature = "__v71"),
+        any(feature = "__pins-100", feature = "__pins-144")
     ))]
     Uart3: {
         RX: [ Pin<PD28, PeripheralA> ],
         TX: [ Pin<PD30, PeripheralA>, Pin<PD31, PeripheralB>, ],
     },
     #[cfg(all(
-        any(feature = "e70", feature = "s70", feature = "v71"),
-        any(feature = "pins-100", feature = "pins-144")
+        any(feature = "__e70", feature = "__s70", feature = "__v71"),
+        any(feature = "__pins-100", feature = "__pins-144")
     ))]
     Uart4: {
         RX: [ Pin<PD18, PeripheralC> ],
diff --git a/hal/src/serial/usart/mod.rs b/hal/src/serial/usart/mod.rs
index ab2ba6a..70e1240 100644
--- a/hal/src/serial/usart/mod.rs
+++ b/hal/src/serial/usart/mod.rs
@@ -89,7 +89,7 @@ use crate::clocks::{Clock, Hertz, HostClock, Pck, Pck4, PeripheralIdentifier};
 use crate::generics::{self, Token};
 #[cfg(feature = "reconfigurable-system-pins")]
 use crate::pac::USART1;
-#[cfg(not(feature = "pins-64"))]
+#[cfg(not(feature = "__pins-64"))]
 use crate::pac::USART2;
 use crate::pac::{
     usart0::us_mr_usart_mode::CHMODESELECT_A as HwChannelMode,
@@ -617,7 +617,7 @@ The [pins]("[<$Usart Pins>]") specified determine what [`UsartMode`]s are valid
 impl_usart!(
     Usart0: {
         SCK: [
-            #[cfg(not(feature = "pins-64"))]
+            #[cfg(not(feature = "__pins-64"))]
             Pin<PB13,PeripheralC>
         ],
         RX: [ Pin<PB0,PeripheralC> ],
@@ -634,7 +634,7 @@ impl_usart!(
     #[cfg(feature = "reconfigurable-system-pins")]
     Usart1: {
         SCK: [
-            #[cfg(not(feature = "pins-64"))]
+            #[cfg(not(feature = "__pins-64"))]
             Pin<PA23,PeripheralA>
         ],
         RX: [ Pin<PA21,PeripheralA> ],
@@ -646,12 +646,12 @@ impl_usart!(
         // DCD: [ Pin<PA26,PeripheralA> ],
         // DTR: [ Pin<PA27,PeripheralA> ],
         CTS: [
-            #[cfg(not(feature = "pins-64"))]
+            #[cfg(not(feature = "__pins-64"))]
             Pin<PA25,PeripheralA>
         ],
         RTS: [ Pin<PA24,PeripheralA> ],
     },
-    #[cfg(not(feature = "pins-64"))]
+    #[cfg(not(feature = "__pins-64"))]
     Usart2: {
         SCK: [ Pin<PD17,PeripheralB> ],
         RX: [ Pin<PD15, PeripheralB> ],
@@ -668,7 +668,7 @@ impl_usart!(
 );
 
 cfg_if::cfg_if! {
-    if #[cfg(all(feature = "usart-spi-host-without-select", not(feature = "pins-64")))] {
+    if #[cfg(all(feature = "usart-spi-host-without-select", not(feature = "__pins-64")))] {
         impl_pins!(
             Usart0: {
                 (/* TX */ Pin<PB1, PeripheralC>, /* RX */ Pin<PB0, PeripheralC>, /* SCK */ Pin<PB13, PeripheralC>): {
diff --git a/hal/src/tc/mod.rs b/hal/src/tc/mod.rs
index b558176..aa667e7 100644
--- a/hal/src/tc/mod.rs
+++ b/hal/src/tc/mod.rs
@@ -705,127 +705,127 @@ impl_tc!(
     Tc0: {
         Ch0: {
             // TIOA0
-            #[cfg(not(feature = "pins-64"))]
+            #[cfg(not(feature = "__pins-64"))]
             TIOA: Pin<PA0, PeripheralB>,
             // TIOB0
-            #[cfg(not(feature = "pins-64"))]
+            #[cfg(not(feature = "__pins-64"))]
             TIOB: Pin<PA1, PeripheralB>,
             // TCLK0
             TCLK: Pin<PA4, PeripheralB>,
         },
         Ch1: {
             // TIOA1
-            #[cfg(not(feature = "pins-64"))]
+            #[cfg(not(feature = "__pins-64"))]
             TIOA: Pin<PA15, PeripheralB>,
             // TIOB1
-            #[cfg(not(feature = "pins-64"))]
+            #[cfg(not(feature = "__pins-64"))]
             TIOB: Pin<PA16, PeripheralB>,
             // TCLK1
-            #[cfg(not(feature = "pins-64"))]
+            #[cfg(not(feature = "__pins-64"))]
             TCLK: Pin<PA28, PeripheralB>,
         },
         Ch2: {
             // TIOA2
-            #[cfg(not(feature = "pins-64"))]
+            #[cfg(not(feature = "__pins-64"))]
             TIOA: Pin<PA26, PeripheralB>,
             // TIOB2
             TIOB: Pin<PA27, PeripheralB>,
             // TCLK2
-            #[cfg(feature = "pins-144")]
+            #[cfg(feature = "__pins-144")]
             TCLK: Pin<PA29, PeripheralB>,
         },
     },
     Tc1: {
         Ch0: {
             // TIOA3
-            #[cfg(feature = "pins-144")]
+            #[cfg(feature = "__pins-144")]
             TIOA: Pin<PC23, PeripheralB>,
             // TIOB3
-            #[cfg(feature = "pins-144")]
+            #[cfg(feature = "__pins-144")]
             TIOB: Pin<PC24, PeripheralB>,
             // TCLK3
-            #[cfg(feature = "pins-144")]
+            #[cfg(feature = "__pins-144")]
             TCLK: Pin<PC25, PeripheralB>,
         },
         Ch1: {
             // TIOA4
-            #[cfg(feature = "pins-144")]
+            #[cfg(feature = "__pins-144")]
             TIOA: Pin<PC26, PeripheralB>,
             // TIOB4
-            #[cfg(feature = "pins-144")]
+            #[cfg(feature = "__pins-144")]
             TIOB: Pin<PC27, PeripheralB>,
             // TCLK4
-            #[cfg(feature = "pins-144")]
+            #[cfg(feature = "__pins-144")]
             TCLK: Pin<PC28, PeripheralB>,
         },
         Ch2: {
             // TIOA5
-            #[cfg(feature = "pins-144")]
+            #[cfg(feature = "__pins-144")]
             TIOA: Pin<PC29, PeripheralB>,
             // TIOB5
-            #[cfg(feature = "pins-144")]
+            #[cfg(feature = "__pins-144")]
             TIOB: Pin<PC30, PeripheralB>,
             // TCLK5
-            #[cfg(feature = "pins-144")]
+            #[cfg(feature = "__pins-144")]
             TCLK: Pin<PC31, PeripheralB>,
         },
     },
     Tc2: {
         Ch0: {
             // TIOA6
-            #[cfg(feature = "pins-144")]
+            #[cfg(feature = "__pins-144")]
             TIOA: Pin<PC5, PeripheralB>,
             // TIOB6
-            #[cfg(feature = "pins-144")]
+            #[cfg(feature = "__pins-144")]
             TIOB: Pin<PC6, PeripheralB>,
             // TCLK6
-            #[cfg(feature = "pins-144")]
+            #[cfg(feature = "__pins-144")]
             TCLK: Pin<PC7, PeripheralB>,
         },
         Ch1: {
             // TIOA7
-            #[cfg(feature = "pins-144")]
+            #[cfg(feature = "__pins-144")]
             TIOA: Pin<PC8, PeripheralB>,
             // TIOB7
-            #[cfg(feature = "pins-144")]
+            #[cfg(feature = "__pins-144")]
             TIOB: Pin<PC9, PeripheralB>,
             // TCLK7
-            #[cfg(feature = "pins-144")]
+            #[cfg(feature = "__pins-144")]
             TCLK: Pin<PC10, PeripheralB>,
         },
         Ch2: {
             // TIOA8
-            #[cfg(feature = "pins-144")]
+            #[cfg(feature = "__pins-144")]
             TIOA: Pin<PC11, PeripheralB>,
-            #[cfg(feature = "pins-144")]
+            #[cfg(feature = "__pins-144")]
             // TIOB8
             TIOB: Pin<PC12, PeripheralB>,
             // TCLK8
-            #[cfg(feature = "pins-144")]
+            #[cfg(feature = "__pins-144")]
             TCLK: Pin<PC14, PeripheralB>,
         },
     },
     Tc3: {
         Ch0: {
             // TIOA9
-            #[cfg(feature = "pins-144")]
+            #[cfg(feature = "__pins-144")]
             TIOA: Pin<PE0, PeripheralB>,
             // TIOB9
-            #[cfg(feature = "pins-144")]
+            #[cfg(feature = "__pins-144")]
             TIOB: Pin<PE1, PeripheralB>,
             // TCLK9
-            #[cfg(feature = "pins-144")]
+            #[cfg(feature = "__pins-144")]
             TCLK: Pin<PE2, PeripheralB>,
         },
         Ch1: {
             // TIOA10
-            #[cfg(feature = "pins-144")]
+            #[cfg(feature = "__pins-144")]
             TIOA: Pin<PE3, PeripheralB>,
             // TIOB10
-            #[cfg(feature = "pins-144")]
+            #[cfg(feature = "__pins-144")]
             TIOB: Pin<PE4, PeripheralB>,
             // TCLK10
-            #[cfg(feature = "pins-144")]
+            #[cfg(feature = "__pins-144")]
             TCLK: Pin<PE5, PeripheralB>,
         },
         Ch2: {
diff --git a/hal/src/usb.rs b/hal/src/usb.rs
index da549ee..5e8d4fb 100644
--- a/hal/src/usb.rs
+++ b/hal/src/usb.rs
@@ -64,6 +64,8 @@ use crate::clocks::{HostClock, PeripheralIdentifier, UpllClock};
 use crate::pac::{usbhs::RegisterBlock, USBHS};
 
 use core::cell::UnsafeCell;
+use core::option::Option;
+use core::result::Result::{Err, Ok};
 
 use cortex_m::interrupt::{self, Mutex};
 use usb_device::bus::{PollResult, UsbBusAllocator};
diff --git a/hal/src/watchdog.rs b/hal/src/watchdog.rs
index bc52c68..1b999ec 100644
--- a/hal/src/watchdog.rs
+++ b/hal/src/watchdog.rs
@@ -1,6 +1,7 @@
 //! Watchdog timer configuration.
 use crate::{generics, pac::WDT};
 
+use core::convert::From;
 use core::marker::PhantomData;
 
 /// The state of the [`Watchdog`].