2 files changed, 12 insertions, 6 deletions
diff --git a/src/peripheral/itm.rs b/src/peripheral/itm.rs
index 17cf869..fd4a2fd 100644
--- a/src/peripheral/itm.rs
+++ b/src/peripheral/itm.rs
@@ -33,17 +33,17 @@ pub struct Stim {
 
 impl Stim {
     /// Writes an `u8` payload into the stimulus port
-    pub fn write_u8(&self, value: u8) {
+    pub fn write_u8(&mut self, value: u8) {
         unsafe { ptr::write_volatile(self.register.get() as *mut u8, value) }
     }
 
     /// Writes an `u16` payload into the stimulus port
-    pub fn write_u16(&self, value: u16) {
+    pub fn write_u16(&mut self, value: u16) {
         unsafe { ptr::write_volatile(self.register.get() as *mut u16, value) }
     }
 
     /// Writes an `u32` payload into the stimulus port
-    pub fn write_u32(&self, value: u32) {
+    pub fn write_u32(&mut self, value: u32) {
         unsafe { ptr::write_volatile(self.register.get(), value) }
     }
 
diff --git a/src/peripheral/mod.rs b/src/peripheral/mod.rs
index d462bdb..bd658a4 100644
--- a/src/peripheral/mod.rs
+++ b/src/peripheral/mod.rs
@@ -9,7 +9,7 @@
 #![allow(private_no_mangle_statics)]
 
 use core::marker::PhantomData;
-use core::ops::Deref;
+use core::ops::{Deref, DerefMut};
 
 use interrupt;
 
@@ -262,8 +262,8 @@ pub struct ITM {
 
 impl ITM {
     /// Returns a pointer to the register block
-    pub fn ptr() -> *const itm::RegisterBlock {
-        0xE000_0000 as *const _
+    pub fn ptr() -> *mut itm::RegisterBlock {
+        0xE000_0000 as *mut _
     }
 }
 
@@ -275,6 +275,12 @@ impl Deref for ITM {
     }
 }
 
+impl DerefMut for ITM {
+    fn deref_mut(&mut self) -> &mut Self::Target {
+        unsafe { &mut *Self::ptr() }
+    }
+}
+
 /// Memory Protection Unit
 pub struct MPU {
     _marker: PhantomData<*const ()>,