LUFA/Common/Common.h

   1 /*
   2              LUFA Library
   3      Copyright (C) Dean Camera, 2009.
   4
   5   dean [at] fourwalledcubicle [dot] com
   6       www.fourwalledcubicle.com
   7 */
   8
   9 /*
  10   Copyright 2009  Dean Camera (dean [at] fourwalledcubicle [dot] com)
  11
  12   Permission to use, copy, modify, and distribute this software
  13   and its documentation for any purpose and without fee is hereby
  14   granted, provided that the above copyright notice appear in all
  15   copies and that both that the copyright notice and this
  16   permission notice and warranty disclaimer appear in supporting
  17   documentation, and that the name of the author not be used in
  18   advertising or publicity pertaining to distribution of the
  19   software without specific, written prior permission.
  20
  21   The author disclaim all warranties with regard to this
  22   software, including all implied warranties of merchantability
  23   and fitness.  In no event shall the author be liable for any
  24   special, indirect or consequential damages or any damages
  25   whatsoever resulting from loss of use, data or profits, whether
  26   in an action of contract, negligence or other tortious action,
  27   arising out of or in connection with the use or performance of
  28   this software.
  29 */
  30
  31 /** \file
  32  *
  33  *  This file contains macros which are common to all library elements, and which may be useful in user code. It
  34  *  also includes other common headers, such as Atomic.h, FunctionAttributes.h and BoardTypes.h.
  35  */
  36
  37 /** @defgroup Group_Common Common Utility Headers - LUFA/Drivers/Common/Common.h
  38  *
  39  *  Common utility headers containing macros, functions, enums and types which are common to all
  40  *  aspects of the library.
  41  *
  42  *  @{
  43  */
  44
  45 /** @defgroup Group_Debugging Debugging Macros
  46  *
  47  *  Macros for debugging use.
  48  */
  49
  50 /** @defgroup Group_BitManip Endian and Bit Macros
  51  *
  52  *  Functions for swapping endianness and reversing bit orders.
  53  */
  54
  55 #ifndef __COMMON_H__
  56 #define __COMMON_H__
  57
  58         /* Includes: */
  59                 #include <avr/io.h>
  60                 #include <stdio.h>
  61                 #include <avr/version.h>
  62
  63                 #include "FunctionAttributes.h"
  64                 #include "BoardTypes.h"
  65
  66                 #include <alloca.h>
  67
  68         /* Public Interface - May be used in end-application: */
  69                 /* Macros: */
  70                         /** Macro for encasing other multi-statement macros. This should be used along with an opening brace
  71                          *  before the start of any multi-statement macro, so that the macros contents as a whole are treated
  72                          *  as a discrete block and not as a list of separate statements which may cause problems when used as
  73                          *  a block (such as inline IF statements).
  74                          */
  75                         #define MACROS                  do
  76
  77                         /** Macro for encasing other multi-statement macros. This should be used along with a preceding closing
  78                          *  brace at the end of any multi-statement macro, so that the macros contents as a whole are treated
  79                          *  as a discrete block and not as a list of separate statements which may cause problems when used as
  80                          *  a block (such as inline IF statements).
  81                          */
  82                         #define MACROE                  while (0)
  83
  84                         /** Defines a volatile NOP statement which cannot be optimized out by the compiler, and thus can always
  85                          *  be set as a breakpoint in the resulting code. Useful for debugging purposes, where the optimizer
  86                          *  removes/reorders code to the point where break points cannot reliably be set.
  87                          *
  88                          *  \ingroup Group_Debugging
  89                          */
  90                         #define JTAG_DEBUG_POINT()      asm volatile ("NOP" ::)
  91
  92                         /** Defines an explicit JTAG break point in the resulting binary via the ASM BREAK statement. When
  93                          *  a JTAG is used, this causes the program execution to halt when reached until manually resumed.
  94                          *
  95                          *  \ingroup Group_Debugging
  96                          */
  97                         #define JTAG_DEBUG_BREAK()      asm volatile ("BREAK" ::)
  98
  99                         /** Macro for testing condition "x" and breaking via JTAG_DEBUG_BREAK() if the condition is false.
 100                          *
 101                          *  \ingroup Group_Debugging
 102                         */
 103                         #define JTAG_DEBUG_ASSERT(x)    MACROS{ if (!(x)) { JTAG_DEBUG_BREAK(); } }MACROE
 104
 105                         /** Macro for testing condition "x" and writing debug data to the serial stream if false. As a
 106                          *  prerequisite for this macro, the serial stream should be configured via the Peripheral/SerialStream driver.
 107                          *
 108                          *  The serial output takes the form "{FILENAME}: Function {FUNCTION NAME}, Line {LINE NUMBER}: Assertion
 109                          *  {x} failed."
 110                          *
 111                          *  \ingroup Group_Debugging
 112                          */
 113                         #define SERIAL_STREAM_ASSERT(x) MACROS{ if (!(x)) { printf_P(PSTR("%s: Function \"%s\", Line %d: "   \
 114                                                                                                                                 "Assertion \"%s\" failed.\r\n"),   \
 115                                                                                                                                 __FILE__, __func__, __LINE__, #x); \
 116                                                         } }MACROE
 117
 118                 /* Inline Functions: */
 119                         /** Function to reverse the individual bits in a byte - i.e. bit 7 is moved to bit 0, bit 6 to bit 1,
 120                          *  etc.
 121                          *
 122                          *  \ingroup Group_BitManip
 123                          *
 124                          *  \param[in] Byte   Byte of data whose bits are to be reversed
 125                          */
 126                         static inline uint8_t BitReverse(uint8_t Byte) ATTR_WARN_UNUSED_RESULT ATTR_CONST;
 127                         static inline uint8_t BitReverse(uint8_t Byte)
 128                         {
 129                                 Byte = (((Byte & 0xF0) >> 4) | ((Byte & 0x0F) << 4));
 130                                 Byte = (((Byte & 0xCC) >> 2) | ((Byte & 0x33) << 2));
 131                                 Byte = (((Byte & 0xAA) >> 1) | ((Byte & 0x55) << 1));
 132
 133                                 return Byte;
 134                         }
 135
 136                         /** Function to reverse the byte ordering of the individual bytes in a 16 bit number.
 137                          *
 138                          *  \ingroup Group_BitManip
 139                          *
 140                          *  \param[in] Word   Word of data whose bytes are to be swapped
 141                          */
 142                         static inline uint16_t SwapEndian_16(uint16_t Word) ATTR_WARN_UNUSED_RESULT ATTR_CONST;
 143                         static inline uint16_t SwapEndian_16(uint16_t Word)
 144                         {
 145                                 return ((Word >> 8) | (Word << 8));
 146                         }
 147
 148                         /** Function to reverse the byte ordering of the individual bytes in a 32 bit number.
 149                          *
 150                          *  \ingroup Group_BitManip
 151                          *
 152                          *  \param[in] DWord   Double word of data whose bytes are to be swapped
 153                          */
 154                         static inline uint32_t SwapEndian_32(uint32_t DWord) ATTR_WARN_UNUSED_RESULT ATTR_CONST;
 155                         static inline uint32_t SwapEndian_32(uint32_t DWord)
 156                         {
 157                                 return (((DWord & 0xFF000000) >> 24) |
 158                                         ((DWord & 0x00FF0000) >> 8)  |
 159                                                 ((DWord & 0x0000FF00) << 8)  |
 160                                                 ((DWord & 0x000000FF) << 24));
 161                         }
 162
 163                         /** Function to reverse the byte ordering of the individual bytes in a n byte number.
 164                          *
 165                          *  \ingroup Group_BitManip
 166                          *
 167                          *  \param[in,out] Data  Pointer to a number containing an even number of bytes to be reversed
 168                          *  \param[in] Bytes  Length of the data in bytes
 169                          */
 170                         static inline void SwapEndian_n(uint8_t* Data, uint8_t Bytes);
 171                         static inline void SwapEndian_n(uint8_t* Data, uint8_t Bytes)
 172                         {
 173                                 uint8_t Temp;
 174
 175                                 while (Bytes)
 176                                 {
 177                                         Temp = *Data;
 178                                         *Data = *(Data + Bytes - 1);
 179                                         *(Data + Bytes) = Temp;
 180
 181                                         Data++;
 182                                         Bytes -= 2;
 183                                 }
 184                         }
 185
 186 #endif
 187
 188 /** @} */