diff --git a/demos/ARMCM3-STM32F103-GCC/board.h b/demos/ARMCM3-STM32F103-GCC/board.h
index 2fd5757e4..8d240d02e 100644
--- a/demos/ARMCM3-STM32F103-GCC/board.h
+++ b/demos/ARMCM3-STM32F103-GCC/board.h
@@ -29,8 +29,6 @@
 #ifndef __STM32F10x_MAP_H
 #include "stm32lib/stm32f10x_map.h"
 #endif
-#define FALSE FALSE
-#define TRUE TRUE
 
 #define BOARD_OLIMEX_STM32_P103
 
diff --git a/ports/ARM7-AT91SAM7X/port.dox b/ports/ARM7-AT91SAM7X/port.dox
index 8c72bfbb6..b8b2c624f 100644
--- a/ports/ARM7-AT91SAM7X/port.dox
+++ b/ports/ARM7-AT91SAM7X/port.dox
@@ -11,3 +11,13 @@
  * @ingroup ARM7
  */
 /** @} */
+
+/**
+ * @defgroup AT91SAM7X_SERIAL UART Support
+ * @{
+ * @brief USART peripherals support.
+ * @details The serial driver supports the AT91SAM7X USART peripherals.
+ *
+ * @ingroup AT91SAM7X
+ */
+/** @} */
diff --git a/ports/ARM7-AT91SAM7X/sam7x_serial.h b/ports/ARM7-AT91SAM7X/sam7x_serial.h
index 18e4a5f88..236f29e5a 100644
--- a/ports/ARM7-AT91SAM7X/sam7x_serial.h
+++ b/ports/ARM7-AT91SAM7X/sam7x_serial.h
@@ -17,14 +17,54 @@
     along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
+/**
+ * @file ports/ARM7-AT91SAM7X/sam7x_serial.h
+ * @brief AT91SAM7X Serial driver macros and structures.
+ * @addtogroup AT91SAM7X_SERIAL
+ * @{
+ */
+
 #ifndef _SAM7X_SERIAL_H_
 #define _SAM7X_SERIAL_H_
 
-/*
- * Configuration parameter, you can change the depth of the queue buffers
- * depending on the requirements of your application.
+/**
+ * @brief Serial buffers size.
+ * @details Configuration parameter, you can change the depth of the queue
+ * buffers depending on the requirements of your application.
+ * @note The default is 128 bytes for both the transmission and receive buffers.
  */
+#if !defined(SERIAL_BUFFERS_SIZE) || defined(__DOXYGEN__)
 #define SERIAL_BUFFERS_SIZE 128
+#endif
+
+/**
+ * @brief Default bit rate.
+ * @details Configuration parameter, at startup the UARTs are configured at
+ * this speed.
+ * @note It is possible to use @p SetUART() in order to change the working
+ *       parameters at runtime.
+ */
+#if !defined(AT91SAM7X_UART_BITRATE) || defined(__DOXYGEN__)
+#define SAM7X_UART_BITRATE 38400
+#endif
+
+/**
+ * @brief UART0 driver enable switch.
+ * @details If set to 1 the support for USART1 is included.
+ * @note The default is 1.
+ */
+#if !defined(USE_LPC214x_UART0) || defined(__DOXYGEN__)
+#define USE_SAM7X_USART0 1
+#endif
+
+/**
+ * @brief UART1 driver enable switch.
+ * @details If set to 1 the support for USART2 is included.
+ * @note The default is 1.
+ */
+#if !defined(USE_LPC214x_UART1) || defined(__DOXYGEN__)
+#define USE_SAM7X_USART1 1
+#endif
 
 #ifdef __cplusplus
 extern "C" {
@@ -37,6 +77,10 @@ extern "C" {
 }
 #endif
 
+/** @cond never*/
 extern FullDuplexDriver COM1, COM2;
+/** @endcond*/
 
 #endif /* _SAM7X_SERIAL_H_ */
+
+/** @} */
diff --git a/ports/ARM7-LPC214x/lpc214x_serial.h b/ports/ARM7-LPC214x/lpc214x_serial.h
index ee60a48f4..fbba6a365 100644
--- a/ports/ARM7-LPC214x/lpc214x_serial.h
+++ b/ports/ARM7-LPC214x/lpc214x_serial.h
@@ -70,9 +70,9 @@
  * @note The default is @p TRUE .
  */
 #if !defined(USE_LPC214x_UART0) || defined(__DOXYGEN__)
-#define USE_LPC214x_UART0 TRUE 
+#define USE_LPC214x_UART0 TRUE
 #endif
- 
+
 /**
  * @brief UART1 driver enable switch.
  * @details If set to @p TRUE the support for USART2 is included.
diff --git a/ports/ARM7-LPC214x/lpc214x_ssp.h b/ports/ARM7-LPC214x/lpc214x_ssp.h
index 411ef5016..01e8b3a93 100644
--- a/ports/ARM7-LPC214x/lpc214x_ssp.h
+++ b/ports/ARM7-LPC214x/lpc214x_ssp.h
@@ -29,7 +29,7 @@
 
 /**
  * @brief SSP bus mutual exclusion control.
- * @details Configuration parameter, if defined this macro enforces mutual
+ * @details Configuration parameter, if set to @p TRUE enforces mutual
  * exclusion when invoking @p sspAcquireBus() and @p sspReleaseBus().
  * @note The internally used synchronization mechanism is a @p Semaphore.
  * @todo Make it use Mutexes or Semaphores like the Heap subsystem.
diff --git a/ports/ARMCM3-STM32F103/stm32_serial.h b/ports/ARMCM3-STM32F103/stm32_serial.h
index 4f0c622b2..7393f718c 100644
--- a/ports/ARMCM3-STM32F103/stm32_serial.h
+++ b/ports/ARMCM3-STM32F103/stm32_serial.h
@@ -63,7 +63,7 @@
  * @note The default is @p TRUE.
  */
 #if !defined(USE_STM32_USART2) || defined(__DOXYGEN__)
-#define USE_STM32_USART2 1
+#define USE_STM32_USART2 TRUE
 #endif
 
 /**