ADD MIXED REGISTER SIZES SUPPORT TO REGISTER PACK

This relies on a memory map implementation based on std::array and specialized
over the register size. PackedRegister can now be used with all supported
register sizes (i.e., widths).

This relates to #7 and the finalization of the API before performance testing.

cppreg.h

@@ -10,10 +10,11 @@
 #define CPPREG_CPPREG_H
 
 
-#include "Register.h"
-#include "Field.h"
-#include "MergeWrite.h"
 #include "Overflow.h"
+#include "MergeWrite.h"
+#include "Register.h"
+#include "RegisterPack.h"
+#include "Field.h"
 
 
 #endif  // CPPREG_CPPREG_H

register/Register.h

@@ -23,10 +23,10 @@ namespace cppreg {
 
     //! Register data structure.
     /**
-     * @tparam address Register address.
+     * @tparam RegAddress Register address.
-     * @tparam width Register total width (i.e., size).
+     * @tparam RegWidth Register total width (i.e., size).
-     * @tparam reset Register reset value (0x0 if unknown).
+     * @tparam ResetValue Register reset value (0x0 if unknown).
-     * @tparam shadow Boolean flag to enable shadow value (enabled if `true`).
+     * @tparam UseShadow shadow Boolean flag to enable shadow value.
      *
      * This data structure will act as a container for fields and is
      * therefore limited to a strict minimum. It only carries information

register/RegisterPack.h

@@ -19,90 +19,108 @@
 namespace cppreg {
 
 
+    //! Memory map implementation.
+    /**
+     * @tparam Address Memory base address.
+     * @tparam N Memory size in bytes.
+     * @tparam W Width in bits of the memory "elements".
+     *
+     * This structure is used to map an array structure onto a memory region.
+     * The width parameter will correspond to the register size.
+     */
+    template <Address_t Address, std::uint32_t N, Width_t W>
+    struct memory_map {
+
+        //! Array type.
+        using mem_array_t = std::array<
+            volatile typename RegisterType<W>::type,
+            N / sizeof(typename RegisterType<W>::type)
+                                      >;
+
+        //! Static reference to memory array.
+        /**
+         * This is defined below.
+         */
+        static mem_array_t& array;
+
+    };
+
+    //! Memory array reference definition.
+    template <Address_t Address, std::uint32_t N, Width_t W>
+    typename memory_map<Address, N, W>::mem_array_t&
+        memory_map<Address, N, W>::array = *(
+            reinterpret_cast<typename memory_map<Address, N, W>::mem_array_t*>(
+                Address
+            )
+        );
+
+
     //! Register pack base implementation.
     /**
+     * @tparam PackBase Pack base address.
+     * @tparam PackByteSize Pack size in bytes.
      */
     template <
         Address_t PackBase,
-        Width_t RegWidth,
+        std::uint32_t PackByteSize
-        std::uint32_t N
     > struct RegisterPack {
 
-        //! Pack register type.
-        using register_type = typename RegisterType<RegWidth>::type;
-
-        //! Type alias for byte array.
-        using mem_array_t =std::array<volatile register_type, N>;
-
         //! Base address.
         constexpr static const Address_t pack_base = PackBase;
 
         //! Pack size in bytes.
-        constexpr static const std::uint32_t size_in_bytes =
+        constexpr static const std::uint32_t size_in_bytes = PackByteSize;
-            N * sizeof(register_type);
-
-        //! Register width in the pack.
-        constexpr static const Width_t register_width = RegWidth;
-
-        //! Reference to the byte array.
-        /**
-         * This is explicitly defined below.
-         */
-        static mem_array_t& _mem_array;
 
     };
 
-    //! RegisterPack byte array reference definition.
-    template <
-        Address_t PackBase,
-        Width_t RegWidth,
-        std::uint32_t N
-    >
-    typename RegisterPack<PackBase, RegWidth, N>::mem_array_t&
-        RegisterPack<PackBase, RegWidth, N>::_mem_array =
-        *(
-            reinterpret_cast<
-                RegisterPack<PackBase, RegWidth, N>::mem_array_t* const
-                >(
-                RegisterPack<PackBase, RegWidth, N>::pack_base
-            )
-        );
-
 
     //! Packed register implementation.
     /**
+     * @tparam RegisterPack Pack to which the register belongs.
+     * @tparam BitOffset Offset in bits for the register with respect to base.
+     * @tparam RegWidth Register width.
+     * @tparam ResetValue Register reset value (0x0 if unknown).
+     * @tparam UseShadow shadow Boolean flag to enable shadow value.
      *
      * This implementation is intended to be used when defining a register
-     * that belongs to a type.
+     * that belongs to a peripheral group.
      */
     template <
         typename RegisterPack,
-        std::uint32_t OffsetInPack,
+        std::uint32_t BitOffset,
-        typename RegisterType<RegisterPack::register_width>::type ResetValue = 0x0,
+        Width_t RegWidth,
+        typename RegisterType<RegWidth>::type ResetValue = 0x0,
         bool UseShadow = false
     >
     struct PackedRegister :
         Register<
-            RegisterPack::pack_base + OffsetInPack,
+            RegisterPack::pack_base + (BitOffset / 8u),
-            RegisterPack::register_width,
+            RegWidth,
             ResetValue,
             UseShadow
                 > {
 
         //! Register type.
         using base_reg = Register<
-            RegisterPack::pack_base + OffsetInPack,
+            RegisterPack::pack_base + (BitOffset / 8u),
-            RegisterPack::register_width,
+            RegWidth,
             ResetValue,
             UseShadow
                                  >;
 
+        //! Memory map type.
+        using mem_map_t = memory_map<
+            RegisterPack::pack_base,
+            RegisterPack::size_in_bytes,
+            RegWidth
+                                    >;
+
         //! Memory modifier.
         /**
          * @return A reference to the writable register memory.
          */
         static typename base_reg::MMIO_t& rw_mem_device() {
-            return RegisterPack::_mem_array[OffsetInPack];
+            return mem_map_t::array[BitOffset / RegWidth];
         };
 
         //! Memory accessor.
@@ -110,14 +128,25 @@ namespace cppreg {
          * @return A reference to the read-only register memory.
          */
         static const typename base_reg::MMIO_t& ro_mem_device() {
-            return RegisterPack::_mem_array[OffsetInPack];
+            return mem_map_t::array[BitOffset / RegWidth];
         };
 
         // Safety check to detect if are overflowing the pack.
-        static_assert((OffsetInPack + (RegisterPack::register_width / 8u)) <=
+        static_assert((BitOffset / 8u) <= RegisterPack::size_in_bytes,
-                      RegisterPack::size_in_bytes,
                       "packed register is overflowing the pack");
 
+        // Safety check to detect if the register is mis-aligned.
+        // A register is mis-aligned if it its offset is not a multiple of
+        // its size and if the pack base address alignment is different from
+        // its type alignment.
+        static_assert((
+                          (BitOffset % RegWidth) == 0
+                          &&
+                          (RegisterPack::pack_address % (RegWidth / 8u) == 0)
+                      ),
+                      "register mis-alignment with respect to pack base");
+
+
     };
 
 
@@ -137,22 +166,35 @@ namespace cppreg {
 
 
     //! Template for loop implementation.
+    /**
+     * @tparam start Start index value.
+     * @tparam end End index value.
+     */
     template <std::size_t start, std::size_t end>
     struct for_loop {
+
+        //! Loop method.
+        /**
+         * @tparam Op Operation to be called at each iteration.
+         *
+         * This will call Op for the range [start, end).
+         */
         template <template <std::size_t> class Op, typename T = void>
-        inline static void iterate(
+        inline static void loop(
             typename std::enable_if<start < end, T>::type* = nullptr
                                ) {
             Op<start>()();
             if (start < end)
                 for_loop<start + 1, end>::template iterate<Op>();
         };
+
+        //! Loop method closure.
         template <template <std::size_t> class Op, typename T = void>
-        inline static void iterate(
+        inline static void loop(
             typename std::enable_if<start >= end, T>::type* = nullptr
                                ) {};
-    };
 
+    };
 
 
 }

single/cppreg-all.h

@@ -388,55 +388,67 @@ namespace cppreg {
 #ifndef CPPREG_REGISTERPACK_H
 #define CPPREG_REGISTERPACK_H
 namespace cppreg {
+    template <Address_t Address, std::uint32_t N, Width_t W>
+    struct memory_map {
+        using mem_array_t = std::array<
+            volatile typename RegisterType<W>::type,
+            N / sizeof(typename RegisterType<W>::type)
+                                      >;
+        static mem_array_t& array;
+    };
+    template <Address_t Address, std::uint32_t N, Width_t W>
+    typename memory_map<Address, N, W>::mem_array_t&
+        memory_map<Address, N, W>::array = *(
+            reinterpret_cast<typename memory_map<Address, N, W>::mem_array_t*>(
+                Address
+            )
+        );
     template <
         Address_t PackBase,
         std::uint32_t PackByteSize
     > struct RegisterPack {
-        using mem_array_t = std::array<volatile std::uint8_t, PackByteSize>;
         constexpr static const Address_t pack_base = PackBase;
         constexpr static const std::uint32_t size_in_bytes = PackByteSize;
-        static mem_array_t& _mem_array;
     };
-    template <
-        Address_t PackBase,
-        std::uint32_t PackByteSize
-    >
-    typename RegisterPack<PackBase, PackByteSize>::mem_array_t&
-        RegisterPack<PackBase, PackByteSize>::_mem_array =
-        *(
-            reinterpret_cast<
-                RegisterPack<PackBase, PackByteSize>::mem_array_t* const
-                >(RegisterPack<PackBase, PackByteSize>::pack_base)
-        );
     template <
         typename RegisterPack,
+        std::uint32_t BitOffset,
         Width_t RegWidth,
-        std::uint32_t OffsetInPack,
         typename RegisterType<RegWidth>::type ResetValue = 0x0,
         bool UseShadow = false
     >
     struct PackedRegister :
         Register<
-            RegisterPack::pack_base + OffsetInPack * 8,
+            RegisterPack::pack_base + (BitOffset / 8u),
             RegWidth,
             ResetValue,
             UseShadow
                 > {
         using base_reg = Register<
-            RegisterPack::pack_base + OffsetInPack * 8,
+            RegisterPack::pack_base + (BitOffset / 8u),
             RegWidth,
             ResetValue,
             UseShadow
                                  >;
+        using mem_map_t = memory_map<
+            RegisterPack::pack_base,
+            RegisterPack::size_in_bytes,
+            RegWidth
+                                    >;
         static typename base_reg::MMIO_t& rw_mem_device() {
-            return RegisterPack::_mem_array[OffsetInPack];
+            return mem_map_t::array[BitOffset / RegWidth];
         };
         static const typename base_reg::MMIO_t& ro_mem_device() {
-            return RegisterPack::_mem_array[OffsetInPack];
+            return mem_map_t::array[BitOffset / RegWidth];
         };
-        static_assert((OffsetInPack + (RegWidth / 8u)) <=
+        static_assert((BitOffset / 8u) <= RegisterPack::size_in_bytes,
-                      RegisterPack::size_in_bytes,
                       "packed register is overflowing the pack");
+        static_assert((
+                          (BitOffset % RegWidth) == 0
+                          &&
+                          (RegisterPack::pack_address % (RegWidth / 8u) == 0)
+                      ),
+                      "register mis-alignment with respect to pack base");
     };
     template <typename... T>
     struct PackIndexing {
@@ -446,7 +458,7 @@ namespace cppreg {
     template <std::size_t start, std::size_t end>
     struct for_loop {
         template <template <std::size_t> class Op, typename T = void>
-        inline static void iterate(
+        inline static void loop(
             typename std::enable_if<start < end, T>::type* = nullptr
                                ) {
             Op<start>()();
@@ -454,7 +466,7 @@ namespace cppreg {
                 for_loop<start + 1, end>::template iterate<Op>();
         };
         template <template <std::size_t> class Op, typename T = void>
-        inline static void iterate(
+        inline static void loop(
             typename std::enable_if<start >= end, T>::type* = nullptr
                                ) {};
     };