diff --git a/source/stm32-f4-exti.ads b/source/stm32-f4-exti.ads
index 5f8b2ab..24aa2fe 100644
--- a/source/stm32-f4-exti.ads
+++ b/source/stm32-f4-exti.ads
@@ -27,12 +27,12 @@ package STM32.F4.EXTI is
 	end record;
 
 	type EXTI_Registers is record
-		IMR:   Event_Set_Register;
-		EMR:   Event_Set_Register;
-		RTSR:  Event_Set_Register;
-		FTSR:  Event_Set_Register;
-		SWIER: Event_Set_Register;
-		PR:    Event_Set_Register;
+		IMR:   Event_Set_Register with Volatile_Full_Access;
+		EMR:   Event_Set_Register with Volatile_Full_Access;
+		RTSR:  Event_Set_Register with Volatile_Full_Access;
+		FTSR:  Event_Set_Register with Volatile_Full_Access;
+		SWIER: Event_Set_Register with Volatile_Full_Access;
+		PR:    Event_Set_Register with Volatile_Full_Access;
 	end record;
 
 	for EXTI_Registers use record
diff --git a/source/stm32-f4-pwr.ads b/source/stm32-f4-pwr.ads
index 9ed0fe0..2d312d6 100644
--- a/source/stm32-f4-pwr.ads
+++ b/source/stm32-f4-pwr.ads
@@ -117,8 +117,8 @@ package STM32.F4.PWR is
 	end record;
 
 	type PWR_Registers is record
-		CR  : Power_Control_Register;
-		CSR : Power_Control_Status_Register;
+		CR  : Power_Control_Register with Volatile_Full_Access;
+		CSR : Power_Control_Status_Register with Volatile_Full_Access;
 	end record with Volatile;
 
 	for PWR_Registers use record
diff --git a/source/stm32-f4-syscfg.ads b/source/stm32-f4-syscfg.ads
index 1bf27b1..a835062 100644
--- a/source/stm32-f4-syscfg.ads
+++ b/source/stm32-f4-syscfg.ads
@@ -114,13 +114,13 @@ package STM32.F4.SysCfg is
 	end record;
 
 	type SYSCFG_Registers is record
-		MEMRMP: Memory_Remap_Register;
-		PMC: Peripherial_Mode_Register;
-		EXTICR1: External_Interrupt_Configuration_1.Register;
-		EXTICR2: External_Interrupt_Configuration_2.Register;
-		EXTICR3: External_Interrupt_Configuration_3.Register;
-		EXTICR4: External_Interrupt_Configuration_4.Register;
-		CMPCR: Compensation_Cell_Control_Register;
+		MEMRMP: Memory_Remap_Register with Volatile_Full_Access;
+		PMC: Peripherial_Mode_Register with Volatile_Full_Access;
+		EXTICR1: External_Interrupt_Configuration_1.Register with Volatile_Full_Access;
+		EXTICR2: External_Interrupt_Configuration_2.Register with Volatile_Full_Access;
+		EXTICR3: External_Interrupt_Configuration_3.Register with Volatile_Full_Access;
+		EXTICR4: External_Interrupt_Configuration_4.Register with Volatile_Full_Access;
+		CMPCR: Compensation_Cell_Control_Register with Volatile_Full_Access;
 	end record;
 
 	for SYSCFG_Registers use record
diff --git a/source/stm32-f4-usart.ads b/source/stm32-f4-usart.ads
index bb96c32..9c6018c 100644
--- a/source/stm32-f4-usart.ads
+++ b/source/stm32-f4-usart.ads
@@ -2,6 +2,8 @@ with Interfaces;
 use Interfaces;
 package STM32.F4.USART is
 	pragma Pure;
+	-- NOTE: USARTs ans UARTs are on APB
+	-- Registers should be written as a whole
 
 	type Status_Register is record
 		PE: Boolean; -- Psrity error
@@ -224,13 +226,13 @@ package STM32.F4.USART is
 	end record;
 
 	type USART_Registers is record
-		SR: Status_Register; -- Status register
-		DR: Unsigned_32; -- Data register
-		BRR: Baud_Rate_Register; -- Baud rate register
-		CR1: Control_Register_1; -- Control register 1
-		CR2: Control_Register_2; -- Control register 2
-		CR3: Control_Register_3; -- Control register 3
-		GTPR: Guard_Time_and_Prescaler_Register; -- Guard time and prescaler register
+		SR: Status_Register with Volatile_Full_Access; -- Status register
+		DR: Unsigned_32 with Volatile_Full_Access; -- Data register
+		BRR: Baud_Rate_Register with Volatile_Full_Access; -- Baud rate register
+		CR1: Control_Register_1 with Volatile_Full_Access; -- Control register 1
+		CR2: Control_Register_2 with Volatile_Full_Access; -- Control register 2
+		CR3: Control_Register_3 with Volatile_Full_Access; -- Control register 3
+		GTPR: Guard_Time_and_Prescaler_Register with Volatile_Full_Access; -- Guard time and prescaler register
 	end record with Volatile;
 	for USART_Registers use record
 		SR   at 16#00# range 0 .. 31;