diff --git a/ports/ARM7-LPC214x/ioports_lld.h b/ports/ARM7-LPC214x/pal_lld.h
similarity index 62%
rename from ports/ARM7-LPC214x/ioports_lld.h
rename to ports/ARM7-LPC214x/pal_lld.h
index cedc9e361..ce56f9562 100644
--- a/ports/ARM7-LPC214x/ioports_lld.h
+++ b/ports/ARM7-LPC214x/pal_lld.h
@@ -18,14 +18,14 @@
 */
 
 /**
- * @file ports/ARM-LPC214x/ioports_lld.h
+ * @file ports/ARM7-LPC214x/ioports_lld.h
  * @brief LPC214x FIO low level driver
- * @addtogroup LPC214x_IOPORTS
+ * @addtogroup LPC214x_PAL
  * @{
  */
 
-#ifndef _IOPORTS_LLD_H_
-#define _IOPORTS_LLD_H_
+#ifndef _PAL_LLD_H_
+#define _PAL_LLD_H_
 
 #ifndef _LPC214X_H_
 #include "lpc214x.h"
@@ -38,7 +38,7 @@
 /**
  * @brief Width, in bits, of an I/O port.
  */
-#define IOPORTS_WIDTH 32
+#define PAL_IOPORTS_WIDTH 32
 
 /**
  * @brief Digital I/O port sized unsigned type.
@@ -73,23 +73,14 @@ typedef FIO * ioportid_t;
  * @brief FIO subsystem initialization.
  * @details Enables the access through the fast registers.
  */
-#define ioport_init_lld() {                                             \
+#define pal_lld_init() {                                                \
   SCS = 3;                                                              \
 }
 
-/**
- * @brief Writes a bits mask on a I/O port.
- *
- * @param[in] port the port identifier
- * @param[in] bits the bits to be written on the specified port
- *
- * @note This function is not meant to be invoked directly by the application
- *       code.
- */
-#define ioport_write_lld(port, bits) ((port)->FIO_PIN = (bits))
-
 /**
  * @brief Reads an I/O port.
+ * @details This function is implemented by reading the FIO PIN register, the
+ *          implementation has no side effects.
  *
  * @param[in] port the port identifier
  * @return the port bits
@@ -97,10 +88,38 @@ typedef FIO * ioportid_t;
  * @note This function is not meant to be invoked directly by the application
  *       code.
  */
-#define ioport_read_lld(port) ((port)->FIO_PIN)
+#define pal_lld_readport(port) ((port)->FIO_PIN)
+
+/**
+ * @brief Reads the output latch.
+ * @details This function is implemented by reading the FIO SET register, the
+ *          implementation has no side effects.
+ *
+ * @param[in] port the port identifier
+ * @return The latched logical states.
+ *
+ * @note This function is not meant to be invoked directly by the application
+ *       code.
+ */
+#define pal_lld_readlatch(port) ((port)->FIO_SET)
+
+/**
+ * @brief Writes a bits mask on a I/O port.
+ * @details This function is implemented by writing the FIO PIN register, the
+ *          implementation has no side effects.
+ *
+ * @param[in] port the port identifier
+ * @param[in] bits the bits to be written on the specified port
+ *
+ * @note This function is not meant to be invoked directly by the application
+ *       code.
+ */
+#define pal_lld_writeport(port, bits) ((port)->FIO_PIN = (bits))
 
 /**
  * @brief Sets a bits mask on a I/O port.
+ * @details This function is implemented by writing the FIO SET register, the
+ *          implementation has no side effects.
  *
  * @param[in] port the port identifier
  * @param[in] bits the bits to be ORed on the specified port
@@ -108,10 +127,12 @@ typedef FIO * ioportid_t;
  * @note This function is not meant to be invoked directly by the application
  *       code.
  */
-#define ioport_set_lld(port, bits) ((port)->FIO_SET = (bits))
+#define pal_lld_setport(port, bits) ((port)->FIO_SET = (bits))
 
 /**
  * @brief Clears a bits mask on a I/O port.
+ * @details This function is implemented by writing the FIO CLR register, the
+ *          implementation has no side effects.
  *
  * @param[in] port the port identifier
  * @param[in] bits the bits to be cleared on the specified port
@@ -119,56 +140,50 @@ typedef FIO * ioportid_t;
  * @note This function is not meant to be invoked directly by the application
  *       code.
  */
-#define ioport_clear_lld(port, bits) ((port)->FIO_CLR = (bits))
-
-/**
- * @brief Toggles a bits mask on a I/O port.
- *
- * @param[in] port the port identifier
- * @param[in] bits the bits to be XORed on the specified port
- *
- * @note This function is not meant to be invoked directly by the application
- *       code.
- */
-#define ioport_toggle_lld(port, bits) ((port)->FIO_PIN ^= (bits))
+#define pal_lld_clearport(port, bits) ((port)->FIO_CLR = (bits))
 
 /**
  * @brief Writes a value on an I/O bus.
+ * @details This function is implemented by writing the FIO PIN and MASK
+ *          registers, the implementation is not atomic because the multiple
+ *          accesses.
  *
- * @param[in] bus the I/O bus, pointer to a @p IOBus structure
- * @param[in] bits the bits to be written on the I/O bus. Values exceeding
- *            the bus width are masked so most significant bits are lost.
+ * @param[in] port the port identifier
+ * @param[in] mask the group mask
+ * @param[in] offset the group bit offset within the port
+ * @param[in] bits the bits to be written. Values exceeding the group width
+ *            are masked.
  *
  * @note This function is not meant to be invoked directly by the application
  *       code.
  */
-#define ioport_writebus_lld(bus, bits) {                                \
-  (port)->FIO_MASK = (bus)->bus_mask;                                   \
-  (port)->FIO_PIN = (bits) << (bus)->bus_offset;                        \
+#define pal_lld_writegroup(port, mask, offset, bits) {                  \
+  (port)->FIO_MASK = (mask) << (offset);                                \
+  (port)->FIO_PIN = (bits) << (offset);                                 \
   (port)->FIO_MASK = 0;                                                 \
 }
 
 /**
- * @brief Reads a value from an I/O bus.
+ * @brief Writes a logical state on an output pad.
  *
- * @param[in] bus the I/O bus, pointer to a @p IOBus structure
- * @return the bus bits
+ * @param[in] port the port identifier
+ * @param[in] pad the pad number within the port
+ * @param[out] bit the logical value, the value must be @p 0 or @p 1
  *
  * @note This function is not meant to be invoked directly by the application
  *       code.
  */
-#define ioport_readbus_lld(bus) \
-  (((bus)->bus_portid->FIO_PIN & (bus)->bus_mask) >> (bus)->bus_offset)
+#define pal_lld_writepad(port, pad, bit) pal_lld_writegroup(port, 1, pad, bit)
 
 /**
  * @brief FIO port setup.
  * @details This function initializes a FIO port, note that this functionality
  *          is LPC214x specific and non portable.
  */
-#define ioport_lpc214x_set_direction_lld(port, dir) {                   \
+#define pal_lld_lpc214x_set_direction(port, dir) {                      \
   (port)->FIO_DIR = (dir);                                              \
 }
 
-#endif /* _IOPORTS_LLD_H_ */
+#endif /* _PAL_LLD_H_ */
 
 /** @} */
diff --git a/ports/ARM7-LPC214x/port.dox b/ports/ARM7-LPC214x/port.dox
index 7db0867b2..69d8d6198 100644
--- a/ports/ARM7-LPC214x/port.dox
+++ b/ports/ARM7-LPC214x/port.dox
@@ -49,14 +49,14 @@
  * @defgroup LPC214x_IOPORTS I/O Ports Support
  * @brief I/O Ports peripherals support.
  * @details This module supports the LPC214x FIO controller. The controller
- * supports the following features (see @ref IOPorts):
+ * supports the following features (see @ref PAL):
  * - 32 bits wide ports.
  * - Atomic set/reset functions.
  * - Atomic set+reset function (atomic bus operations).
  * - Output latched regardless of the pad setting.
  * - Direct read of input pads regardless of the pad setting.
  * .
- * The only non atomic operations are bit toggling and bus writing.
+ * The only non atomic operations are bit toggling and bus/group writing.
  *
  * @ingroup LPC214x
  */
diff --git a/ports/ARMCM3-STM32F103/pal_lld.h b/ports/ARMCM3-STM32F103/pal_lld.h
index 33e6f959a..ec4896add 100644
--- a/ports/ARMCM3-STM32F103/pal_lld.h
+++ b/ports/ARMCM3-STM32F103/pal_lld.h
@@ -132,7 +132,7 @@ typedef GPIO_TypeDef * ioportid_t;
 
 /**
  * @brief Reads the output latch.
- * @details This function is implemented by reading the GPIO oDR register, the
+ * @details This function is implemented by reading the GPIO ODR register, the
  *          implementation has no side effects.
  *
  * @param[in] port the port identifier
@@ -192,7 +192,6 @@ typedef GPIO_TypeDef * ioportid_t;
  * @param[in] offset the group bit offset within the port
  * @param[in] bits the bits to be written. Values exceeding the group width
  *            are masked.
- * @return The group logical states.
  *
  * @note This function is not meant to be invoked directly by the application
  *       code.
diff --git a/src/lib/pal.h b/src/lib/pal.h
index 76bf111b6..662df87ee 100644
--- a/src/lib/pal.h
+++ b/src/lib/pal.h
@@ -239,7 +239,6 @@ typedef struct {
  * @param[in] offset the group bit offset within the port
  * @param[in] bits the bits to be written. Values exceeding the group width
  *            are masked.
- * @return The group logical states.
  */
 #if !defined(pal_lld_writegroup) || defined(__DOXYGEN__)
 #define palWriteGroup(port, mask, offset, bits) {                       \
diff --git a/src/templates/pal_lld.h b/src/templates/pal_lld.h
index 246ab8d9f..38d0253e2 100644
--- a/src/templates/pal_lld.h
+++ b/src/templates/pal_lld.h
@@ -171,7 +171,6 @@ typedef uint32_t ioportid_t;
  * @param[in] offset the group bit offset within the port
  * @param[in] bits the bits to be written. Values exceeding the group width
  *            are masked.
- * @return The group logical states.
  *
  * @note This function is not meant to be invoked directly by the application
  *       code.