diff --git a/embassy-nrf-examples/Cargo.toml b/embassy-nrf-examples/Cargo.toml
index 432e8950..2a5b52dd 100644
--- a/embassy-nrf-examples/Cargo.toml
+++ b/embassy-nrf-examples/Cargo.toml
@@ -28,5 +28,4 @@ cortex-m = { version = "0.7.1", features = ["inline-asm"] }
 cortex-m-rt = "0.6.13"
 embedded-hal    = { version = "0.2.4" }
 panic-probe = "0.1.0"
-nrf52840-hal    = { version = "0.12.1" }
 futures = { version = "0.3.8", default-features = false, features = ["async-await"] }
\ No newline at end of file
diff --git a/embassy-nrf-examples/src/bin/buffered_uart.rs b/embassy-nrf-examples/src/bin/buffered_uart.rs
index 80b24d2b..c7c82e84 100644
--- a/embassy-nrf-examples/src/bin/buffered_uart.rs
+++ b/embassy-nrf-examples/src/bin/buffered_uart.rs
@@ -7,20 +7,16 @@
 
 #[path = "../example_common.rs"]
 mod example_common;
-use core::mem;
-
-use embassy_nrf::gpio::NoPin;
-use example_common::*;
 
 use cortex_m_rt::entry;
 use defmt::panic;
-use futures::pin_mut;
-use nrf52840_hal::clocks;
-
 use embassy::executor::{task, Executor};
 use embassy::io::{AsyncBufReadExt, AsyncWriteExt};
 use embassy::util::{Forever, Steal};
+use embassy_nrf::gpio::NoPin;
 use embassy_nrf::{buffered_uarte::BufferedUarte, interrupt, peripherals, rtc, uarte, Peripherals};
+use example_common::*;
+use futures::pin_mut;
 
 #[task]
 async fn run() {
@@ -85,14 +81,9 @@ fn main() -> ! {
 
     let p = unwrap!(embassy_nrf::Peripherals::take());
 
-    clocks::Clocks::new(unsafe { mem::transmute(()) })
-        .enable_ext_hfosc()
-        .set_lfclk_src_external(clocks::LfOscConfiguration::NoExternalNoBypass)
-        .start_lfclk();
-
+    unsafe { embassy_nrf::system::configure(Default::default()) };
     let rtc = RTC.put(rtc::RTC::new(p.RTC1, interrupt::take!(RTC1)));
     rtc.start();
-
     unsafe { embassy::time::set_clock(rtc) };
 
     let alarm = ALARM.put(rtc.alarm0());
diff --git a/embassy-nrf-examples/src/bin/executor_fairness_test.rs b/embassy-nrf-examples/src/bin/executor_fairness_test.rs
index cfcfd949..67610ef0 100644
--- a/embassy-nrf-examples/src/bin/executor_fairness_test.rs
+++ b/embassy-nrf-examples/src/bin/executor_fairness_test.rs
@@ -9,7 +9,6 @@
 mod example_common;
 use example_common::*;
 
-use core::mem;
 use core::task::Poll;
 use cortex_m_rt::entry;
 use defmt::panic;
@@ -18,7 +17,6 @@ use embassy::time::{Duration, Instant, Timer};
 use embassy::util::Forever;
 use embassy_nrf::peripherals;
 use embassy_nrf::{interrupt, rtc};
-use nrf52840_hal::clocks;
 
 #[task]
 async fn run1() {
@@ -54,14 +52,9 @@ fn main() -> ! {
 
     let p = unwrap!(embassy_nrf::Peripherals::take());
 
-    clocks::Clocks::new(unsafe { mem::transmute(()) })
-        .enable_ext_hfosc()
-        .set_lfclk_src_external(clocks::LfOscConfiguration::NoExternalNoBypass)
-        .start_lfclk();
-
+    unsafe { embassy_nrf::system::configure(Default::default()) };
     let rtc = RTC.put(rtc::RTC::new(p.RTC1, interrupt::take!(RTC1)));
     rtc.start();
-
     unsafe { embassy::time::set_clock(rtc) };
 
     let alarm = ALARM.put(rtc.alarm0());
diff --git a/embassy-nrf-examples/src/bin/multiprio.rs b/embassy-nrf-examples/src/bin/multiprio.rs
index 017de3c0..aa2824f6 100644
--- a/embassy-nrf-examples/src/bin/multiprio.rs
+++ b/embassy-nrf-examples/src/bin/multiprio.rs
@@ -62,14 +62,10 @@
 
 #[path = "../example_common.rs"]
 mod example_common;
-use core::mem;
-
 use example_common::*;
 
 use cortex_m_rt::entry;
 use defmt::panic;
-use nrf52840_hal::clocks;
-
 use embassy::executor::{task, Executor, InterruptExecutor};
 use embassy::interrupt::InterruptExt;
 use embassy::time::{Duration, Instant, Timer};
@@ -132,11 +128,7 @@ fn main() -> ! {
 
     let p = unwrap!(embassy_nrf::Peripherals::take());
 
-    clocks::Clocks::new(unsafe { mem::transmute(()) })
-        .enable_ext_hfosc()
-        .set_lfclk_src_external(clocks::LfOscConfiguration::NoExternalNoBypass)
-        .start_lfclk();
-
+    unsafe { embassy_nrf::system::configure(Default::default()) };
     let rtc = RTC.put(rtc::RTC::new(p.RTC1, interrupt::take!(RTC1)));
     rtc.start();
     unsafe { embassy::time::set_clock(rtc) };
diff --git a/embassy-nrf-examples/src/bin/ppi.rs b/embassy-nrf-examples/src/bin/ppi.rs
index 87854fa5..382c18f8 100644
--- a/embassy-nrf-examples/src/bin/ppi.rs
+++ b/embassy-nrf-examples/src/bin/ppi.rs
@@ -20,7 +20,6 @@ use embassy_nrf::gpio::{Input, Level, Output, OutputDrive, Pull};
 use embassy_nrf::gpiote::{self, InputChannel, InputChannelPolarity};
 use embassy_nrf::ppi::Ppi;
 use embassy_nrf::{interrupt, Peripherals};
-use futures::future;
 use gpiote::{OutputChannel, OutputChannelPolarity};
 
 #[task]
diff --git a/embassy-nrf-examples/src/bin/raw_spawn.rs b/embassy-nrf-examples/src/bin/raw_spawn.rs
index 1dd60403..f8e021d9 100644
--- a/embassy-nrf-examples/src/bin/raw_spawn.rs
+++ b/embassy-nrf-examples/src/bin/raw_spawn.rs
@@ -3,19 +3,17 @@
 
 #[path = "../example_common.rs"]
 mod example_common;
-use core::mem;
-
-use embassy::executor::raw::Task;
 use example_common::*;
 
+use core::mem;
 use cortex_m_rt::entry;
 use defmt::panic;
+use embassy::executor::raw::Task;
 use embassy::executor::Executor;
 use embassy::time::{Duration, Timer};
 use embassy::util::Forever;
 use embassy_nrf::peripherals;
 use embassy_nrf::{interrupt, rtc};
-use nrf52840_hal::clocks;
 
 async fn run1() {
     loop {
@@ -41,14 +39,9 @@ fn main() -> ! {
 
     let p = unwrap!(embassy_nrf::Peripherals::take());
 
-    clocks::Clocks::new(unsafe { mem::transmute(()) })
-        .enable_ext_hfosc()
-        .set_lfclk_src_external(clocks::LfOscConfiguration::NoExternalNoBypass)
-        .start_lfclk();
-
+    unsafe { embassy_nrf::system::configure(Default::default()) };
     let rtc = RTC.put(rtc::RTC::new(p.RTC1, interrupt::take!(RTC1)));
     rtc.start();
-
     unsafe { embassy::time::set_clock(rtc) };
 
     let alarm = ALARM.put(rtc.alarm0());
diff --git a/embassy-nrf-examples/src/bin/spim.rs b/embassy-nrf-examples/src/bin/spim.rs
index 77058bf2..5e2340ff 100644
--- a/embassy-nrf-examples/src/bin/spim.rs
+++ b/embassy-nrf-examples/src/bin/spim.rs
@@ -8,8 +8,6 @@
 #[path = "../example_common.rs"]
 mod example_common;
 
-use core::mem;
-
 use cortex_m_rt::entry;
 use defmt::panic;
 use embassy::executor::{task, Executor};
@@ -22,7 +20,6 @@ use embassy_traits::spi::FullDuplex;
 use embedded_hal::digital::v2::*;
 use example_common::*;
 use futures::pin_mut;
-use nrf52840_hal::clocks;
 
 #[task]
 async fn run() {
@@ -98,13 +95,10 @@ fn main() -> ! {
 
     let p = unwrap!(embassy_nrf::Peripherals::take());
 
-    clocks::Clocks::new(unsafe { mem::transmute(()) })
-        .enable_ext_hfosc()
-        .set_lfclk_src_external(clocks::LfOscConfiguration::NoExternalNoBypass)
-        .start_lfclk();
-
+    unsafe { embassy_nrf::system::configure(Default::default()) };
     let rtc = RTC.put(rtc::RTC::new(p.RTC1, interrupt::take!(RTC1)));
     rtc.start();
+    unsafe { embassy::time::set_clock(rtc) };
 
     unsafe { embassy::time::set_clock(rtc) };
 
diff --git a/embassy-nrf-examples/src/bin/timer.rs b/embassy-nrf-examples/src/bin/timer.rs
index 41e5d77a..47d5d677 100644
--- a/embassy-nrf-examples/src/bin/timer.rs
+++ b/embassy-nrf-examples/src/bin/timer.rs
@@ -7,8 +7,6 @@
 
 #[path = "../example_common.rs"]
 mod example_common;
-use core::mem;
-
 use example_common::*;
 
 use cortex_m_rt::entry;
@@ -16,9 +14,7 @@ use defmt::panic;
 use embassy::executor::{task, Executor};
 use embassy::time::{Duration, Timer};
 use embassy::util::Forever;
-use embassy_nrf::peripherals;
-use embassy_nrf::{interrupt, rtc};
-use nrf52840_hal::clocks;
+use embassy_nrf::{interrupt, peripherals, rtc};
 
 #[task]
 async fn run1() {
@@ -44,16 +40,11 @@ static EXECUTOR: Forever<Executor> = Forever::new();
 fn main() -> ! {
     info!("Hello World!");
 
-    clocks::Clocks::new(unsafe { mem::transmute(()) })
-        .enable_ext_hfosc()
-        .set_lfclk_src_external(clocks::LfOscConfiguration::NoExternalNoBypass)
-        .start_lfclk();
-
     let p = unwrap!(embassy_nrf::Peripherals::take());
 
+    unsafe { embassy_nrf::system::configure(Default::default()) };
     let rtc = RTC.put(rtc::RTC::new(p.RTC1, interrupt::take!(RTC1)));
     rtc.start();
-
     unsafe { embassy::time::set_clock(rtc) };
 
     let alarm = ALARM.put(rtc.alarm0());
diff --git a/embassy-nrf-examples/src/bin/uart.rs b/embassy-nrf-examples/src/bin/uart.rs
index d8644167..9bbcb3d4 100644
--- a/embassy-nrf-examples/src/bin/uart.rs
+++ b/embassy-nrf-examples/src/bin/uart.rs
@@ -7,9 +7,6 @@
 
 #[path = "../example_common.rs"]
 mod example_common;
-use core::mem;
-
-use embassy_nrf::gpio::NoPin;
 use example_common::*;
 
 use cortex_m_rt::entry;
@@ -17,9 +14,9 @@ use defmt::panic;
 use embassy::executor::{task, Executor};
 use embassy::traits::uart::{Read, Write};
 use embassy::util::{Forever, Steal};
+use embassy_nrf::gpio::NoPin;
 use embassy_nrf::{interrupt, peripherals, rtc, uarte, Peripherals};
 use futures::pin_mut;
-use nrf52840_hal::clocks;
 
 #[task]
 async fn run() {
@@ -88,14 +85,9 @@ fn main() -> ! {
 
     let p = unwrap!(embassy_nrf::Peripherals::take());
 
-    clocks::Clocks::new(unsafe { mem::transmute(()) })
-        .enable_ext_hfosc()
-        .set_lfclk_src_external(clocks::LfOscConfiguration::NoExternalNoBypass)
-        .start_lfclk();
-
+    unsafe { embassy_nrf::system::configure(Default::default()) };
     let rtc = RTC.put(rtc::RTC::new(p.RTC1, interrupt::take!(RTC1)));
     rtc.start();
-
     unsafe { embassy::time::set_clock(rtc) };
 
     let alarm = ALARM.put(rtc.alarm0());
diff --git a/embassy-nrf-examples/src/example_common.rs b/embassy-nrf-examples/src/example_common.rs
index d16964d4..54d63383 100644
--- a/embassy-nrf-examples/src/example_common.rs
+++ b/embassy-nrf-examples/src/example_common.rs
@@ -1,7 +1,6 @@
 #![macro_use]
 
 use defmt_rtt as _; // global logger
-use nrf52840_hal as _;
 use panic_probe as _;
 
 pub use defmt::*;
diff --git a/embassy-nrf/Cargo.toml b/embassy-nrf/Cargo.toml
index 3ab2c60b..8ec5b087 100644
--- a/embassy-nrf/Cargo.toml
+++ b/embassy-nrf/Cargo.toml
@@ -31,8 +31,8 @@ embedded-hal    = { version = "0.2.4" }
 embedded-dma    = { version = "0.1.2" }
 futures     = { version = "0.3.5", default-features = false }
 
-nrf52810-pac  = { version = "0.9.0", optional = true }
-nrf52811-pac  = { version = "0.9.1", optional = true }
-nrf52832-pac  = { version = "0.9.0", optional = true }
-nrf52833-pac  = { version = "0.9.0", optional = true }
-nrf52840-pac  = { version = "0.9.0", optional = true }
+nrf52810-pac  = { version = "0.9.0", optional = true, features = [ "rt" ]}
+nrf52811-pac  = { version = "0.9.1", optional = true, features = [ "rt" ]}
+nrf52832-pac  = { version = "0.9.0", optional = true, features = [ "rt" ]}
+nrf52833-pac  = { version = "0.9.0", optional = true, features = [ "rt" ]}
+nrf52840-pac  = { version = "0.9.0", optional = true, features = [ "rt" ]}
diff --git a/embassy-nrf/src/lib.rs b/embassy-nrf/src/lib.rs
index 042050d2..33d764fb 100644
--- a/embassy-nrf/src/lib.rs
+++ b/embassy-nrf/src/lib.rs
@@ -92,6 +92,7 @@ pub mod qspi;
 pub mod rtc;
 pub mod saadc;
 pub mod spim;
+pub mod system;
 pub mod timer;
 pub mod uarte;
 
diff --git a/embassy-nrf/src/system.rs b/embassy-nrf/src/system.rs
new file mode 100644
index 00000000..5d36e66f
--- /dev/null
+++ b/embassy-nrf/src/system.rs
@@ -0,0 +1,76 @@
+use crate::pac;
+
+pub enum HfclkSource {
+    Internal,
+    ExternalXtal,
+}
+
+pub enum LfclkSource {
+    InternalRC,
+    Synthesized,
+    ExternalXtal,
+    ExternalLowSwing,
+    ExternalFullSwing,
+}
+
+#[non_exhaustive]
+pub struct Config {
+    pub hfclk_source: HfclkSource,
+    pub lfclk_source: LfclkSource,
+}
+
+impl Default for Config {
+    fn default() -> Self {
+        Self {
+            // There are hobby nrf52 boards out there without external XTALs...
+            // Default everything to internal so it Just Works. User can enable external
+            // xtals if they know they have them.
+            hfclk_source: HfclkSource::Internal,
+            lfclk_source: LfclkSource::InternalRC,
+        }
+    }
+}
+
+/// safety: must only call once.
+pub unsafe fn configure(config: Config) {
+    let r = &*pac::CLOCK::ptr();
+
+    // Start HFCLK.
+    match config.hfclk_source {
+        HfclkSource::Internal => {}
+        HfclkSource::ExternalXtal => {
+            // Datasheet says this is likely to take 0.36ms
+            r.events_hfclkstarted.write(|w| unsafe { w.bits(0) });
+            r.tasks_hfclkstart.write(|w| unsafe { w.bits(1) });
+            while r.events_hfclkstarted.read().bits() == 0 {}
+        }
+    }
+
+    // Configure LFCLK.
+    match config.lfclk_source {
+        LfclkSource::InternalRC => r.lfclksrc.write(|w| w.src().rc()),
+        LfclkSource::Synthesized => r.lfclksrc.write(|w| w.src().synth()),
+
+        LfclkSource::ExternalXtal => r.lfclksrc.write(move |w| w.src().xtal()),
+
+        LfclkSource::ExternalLowSwing => r.lfclksrc.write(move |w| {
+            w.src().xtal();
+            w.external().enabled();
+            w.bypass().disabled();
+            w
+        }),
+        LfclkSource::ExternalFullSwing => r.lfclksrc.write(move |w| {
+            w.src().xtal();
+            w.external().enabled();
+            w.bypass().enabled();
+            w
+        }),
+    }
+
+    // Start LFCLK.
+    // Datasheet says this could take 100us from synth source
+    // 600us from rc source, 0.25s from an external source.
+    r.events_lfclkstarted.write(|w| unsafe { w.bits(0) });
+    r.tasks_lfclkstart.write(|w| unsafe { w.bits(1) });
+    while r.events_lfclkstarted.read().bits() == 0 {}
+}