LUFA/Common/Common.h

   1 /*
   2              LUFA Library
   3      Copyright (C) Dean Camera, 2010.
   4
   5   dean [at] fourwalledcubicle [dot] com
   6       www.fourwalledcubicle.com
   7 */
   8
   9 /*
  10   Copyright 2010  Dean Camera (dean [at] fourwalledcubicle [dot] com)
  11
  12   Permission to use, copy, modify, distribute, and sell this
  13   software and its documentation for any purpose is hereby granted
  14   without fee, provided that the above copyright notice appear in
  15   all 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
  61                 #include "FunctionAttributes.h"
  62                 #include "BoardTypes.h"
  63
  64         /* Public Interface - May be used in end-application: */
  65                 /* Macros: */
  66                         /** Macro for encasing other multi-statement macros. This should be used along with an opening brace
  67                          *  before the start of any multi-statement macro, so that the macros contents as a whole are treated
  68                          *  as a discrete block and not as a list of separate statements which may cause problems when used as
  69                          *  a block (such as inline IF statements).
  70                          */
  71                         #define MACROS                  do
  72
  73                         /** Macro for encasing other multi-statement macros. This should be used along with a preceding closing
  74                          *  brace at the end of any multi-statement macro, so that the macros contents as a whole are treated
  75                          *  as a discrete block and not as a list of separate statements which may cause problems when used as
  76                          *  a block (such as inline IF statements).
  77                          */
  78                         #define MACROE                  while (0)
  79
  80                         /** Defines a volatile NOP statement which cannot be optimized out by the compiler, and thus can always
  81                          *  be set as a breakpoint in the resulting code. Useful for debugging purposes, where the optimizer
  82                          *  removes/reorders code to the point where break points cannot reliably be set.
  83                          *
  84                          *  \ingroup Group_Debugging
  85                          */
  86                         #define JTAG_DEBUG_POINT()      asm volatile ("NOP" ::)
  87
  88                         /** Defines an explicit JTAG break point in the resulting binary via the ASM BREAK statement. When
  89                          *  a JTAG is used, this causes the program execution to halt when reached until manually resumed.
  90                          *
  91                          *  \ingroup Group_Debugging
  92                          */
  93                         #define JTAG_DEBUG_BREAK()      asm volatile ("BREAK" ::)
  94
  95                         /** Macro for testing condition "x" and breaking via JTAG_DEBUG_BREAK() if the condition is false.
  96                          *
  97                          *  \ingroup Group_Debugging
  98                         */
  99                         #define JTAG_DEBUG_ASSERT(x)    MACROS{ if (!(x)) { JTAG_DEBUG_BREAK(); } }MACROE
 100
 101                         /** Macro for testing condition "x" and writing debug data to the serial stream if false. As a
 102                          *  prerequisite for this macro, the serial stream should be configured via the Peripheral/SerialStream driver.
 103                          *
 104                          *  The serial output takes the form "{FILENAME}: Function {FUNCTION NAME}, Line {LINE NUMBER}: Assertion
 105                          *  {x} failed."
 106                          *
 107                          *  \ingroup Group_Debugging
 108                          */
 109                         #define SERIAL_STREAM_ASSERT(x) MACROS{ if (!(x)) { printf_P(PSTR("%s: Function \"%s\", Line %d: "   \
 110                                                                                                                                 "Assertion \"%s\" failed.\r\n"),   \
 111                                                                                                                                 __FILE__, __func__, __LINE__, #x); \
 112                                                         } }MACROE
 113
 114                 /* Inline Functions: */
 115                         /** Function to reverse the individual bits in a byte - i.e. bit 7 is moved to bit 0, bit 6 to bit 1,
 116                          *  etc.
 117                          *
 118                          *  \ingroup Group_BitManip
 119                          *
 120                          *  \param[in] Byte   Byte of data whose bits are to be reversed
 121                          */
 122                         static inline uint8_t BitReverse(uint8_t Byte) ATTR_WARN_UNUSED_RESULT ATTR_CONST;
 123                         static inline uint8_t BitReverse(uint8_t Byte)
 124                         {
 125                                 Byte = (((Byte & 0xF0) >> 4) | ((Byte & 0x0F) << 4));
 126                                 Byte = (((Byte & 0xCC) >> 2) | ((Byte & 0x33) << 2));
 127                                 Byte = (((Byte & 0xAA) >> 1) | ((Byte & 0x55) << 1));
 128
 129                                 return Byte;
 130                         }
 131
 132                         /** Function to reverse the byte ordering of the individual bytes in a 16 bit number.
 133                          *
 134                          *  \ingroup Group_BitManip
 135                          *
 136                          *  \param[in] Word   Word of data whose bytes are to be swapped
 137                          */
 138                         static inline uint16_t SwapEndian_16(uint16_t Word) ATTR_WARN_UNUSED_RESULT ATTR_CONST;
 139                         static inline uint16_t SwapEndian_16(uint16_t Word)
 140                         {
 141                                 return ((Word >> 8) | (Word << 8));
 142                         }
 143
 144                         /** Function to reverse the byte ordering of the individual bytes in a 32 bit number.
 145                          *
 146                          *  \ingroup Group_BitManip
 147                          *
 148                          *  \param[in] DWord   Double word of data whose bytes are to be swapped
 149                          */
 150                         static inline uint32_t SwapEndian_32(uint32_t DWord) ATTR_WARN_UNUSED_RESULT ATTR_CONST;
 151                         static inline uint32_t SwapEndian_32(uint32_t DWord)
 152                         {
 153                                 return (((DWord & 0xFF000000) >> 24) |
 154                                         ((DWord & 0x00FF0000) >> 8)  |
 155                                                 ((DWord & 0x0000FF00) << 8)  |
 156                                                 ((DWord & 0x000000FF) << 24));
 157                         }
 158
 159                         /** Function to reverse the byte ordering of the individual bytes in a n byte number.
 160                          *
 161                          *  \ingroup Group_BitManip
 162                          *
 163                          *  \param[in,out] Data  Pointer to a number containing an even number of bytes to be reversed
 164                          *  \param[in] Bytes  Length of the data in bytes
 165                          */
 166                         static inline void SwapEndian_n(uint8_t* Data, uint8_t Bytes);
 167                         static inline void SwapEndian_n(uint8_t* Data, uint8_t Bytes)
 168                         {
 169                                 uint8_t Temp;
 170
 171                                 while (Bytes)
 172                                 {
 173                                         Temp = *Data;
 174                                         *Data = *(Data + Bytes - 1);
 175                                         *(Data + Bytes) = Temp;
 176
 177                                         Data++;
 178                                         Bytes -= 2;
 179                                 }
 180                         }
 181
 182 #endif
 183
 184 /** @} */