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Diffstat (limited to 'include/avr/sfr_defs.h')
| -rw-r--r-- | include/avr/sfr_defs.h | 272 |
1 files changed, 272 insertions, 0 deletions
diff --git a/include/avr/sfr_defs.h b/include/avr/sfr_defs.h new file mode 100644 index 0000000000..2b8392689a --- /dev/null +++ b/include/avr/sfr_defs.h @@ -0,0 +1,272 @@ +/** + * @file + * + * @brief Macros for Accessing AVR Special Function Registers + */ + +/* Copyright (c) 2002, Marek Michalkiewicz <marekm@amelek.gda.pl> + All rights reserved. + + Redistribution and use in source and binary forms, with or without + modification, are permitted provided that the following conditions are met: + + * Redistributions of source code must retain the above copyright + notice, this list of conditions and the following disclaimer. + + * Redistributions in binary form must reproduce the above copyright + notice, this list of conditions and the following disclaimer in + the documentation and/or other materials provided with the + distribution. + + * Neither the name of the copyright holders nor the names of + contributors may be used to endorse or promote products derived + from this software without specific prior written permission. + + THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" + AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE + LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR + CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF + SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS + INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN + CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) + ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE + POSSIBILITY OF SUCH DAMAGE. */ + +/* avr/sfr_defs.h - macros for accessing AVR special function registers */ + + +#ifndef _AVR_SFR_DEFS_H_ +#define _AVR_SFR_DEFS_H_ 1 + +/** + * @defgroup avr_sfr_notes Additional notes from <avr/sfr_defs.h> + * + * @ingroup avr_sfr + * + * The @c <avr/sfr_defs.h> file is included by all of the @c <avr/ioXXXX.h> + * files, which use macros defined here to make the special function register + * definitions look like C variables or simple constants, depending on the + * <tt>_SFR_ASM_COMPAT</tt> define. Some examples from @c <avr/iocanxx.h> to + * show how to define such macros: + * + * @code + * #define PORTA _SFR_IO8(0x02) + * #define EEAR _SFR_IO16(0x21) + * #define UDR0 _SFR_MEM8(0xC6) + * #define TCNT3 _SFR_MEM16(0x94) + * #define CANIDT _SFR_MEM32(0xF0) + * @endcode + * + * If @c _SFR_ASM_COMPAT is not defined, C programs can use names like + * <tt>PORTA</tt> directly in C expressions (also on the left side of + * assignment operators) and GCC will do the right thing (use short I/O + * instructions if possible). The @c __SFR_OFFSET definition is not used in + * any way in this case. + * + * Define @c _SFR_ASM_COMPAT as 1 to make these names work as simple constants + * (addresses of the I/O registers). This is necessary when included in + * preprocessed assembler (*.S) source files, so it is done automatically if + * @c __ASSEMBLER__ is defined. By default, all addresses are defined as if + * they were memory addresses (used in @c lds/sts instructions). To use these + * addresses in @c in/out instructions, you must subtract 0x20 from them. + * + * For more backwards compatibility, insert the following at the start of your + * old assembler source file: + * + * @code + * #define __SFR_OFFSET 0 + * @endcode + * + * This automatically subtracts 0x20 from I/O space addresses, but it's a + * hack, so it is recommended to change your source: wrap such addresses in + * macros defined here, as shown below. After this is done, the + * <tt>__SFR_OFFSET</tt> definition is no longer necessary and can be removed. + + * Real example - this code could be used in a boot loader that is portable + * between devices with @c SPMCR at different addresses. + * + * @verbatim + * <avr/iom163.h>: #define SPMCR _SFR_IO8(0x37) + * <avr/iom128.h>: #define SPMCR _SFR_MEM8(0x68) + * @endverbatim + * + * @code + * #if _SFR_IO_REG_P(SPMCR) + * out _SFR_IO_ADDR(SPMCR), r24 + * #else + * sts _SFR_MEM_ADDR(SPMCR), r24 + * #endif + * @endcode + * + * You can use the @c in/out/cbi/sbi/sbic/sbis instructions, without the + * <tt>_SFR_IO_REG_P</tt> test, if you know that the register is in the I/O + * space (as with @c SREG, for example). If it isn't, the assembler will + * complain (I/O address out of range 0...0x3f), so this should be fairly + * safe. + * + * If you do not define @c __SFR_OFFSET (so it will be 0x20 by default), all + * special register addresses are defined as memory addresses (so @c SREG is + * 0x5f), and (if code size and speed are not important, and you don't like + * the ugly \#if above) you can always use lds/sts to access them. But, this + * will not work if <tt>__SFR_OFFSET</tt> != 0x20, so use a different macro + * (defined only if <tt>__SFR_OFFSET</tt> == 0x20) for safety: + * + * @code + * sts _SFR_ADDR(SPMCR), r24 + * @endcode + * + * In C programs, all 3 combinations of @c _SFR_ASM_COMPAT and + * <tt>__SFR_OFFSET</tt> are supported - the @c _SFR_ADDR(SPMCR) macro can be + * used to get the address of the @c SPMCR register (0x57 or 0x68 depending on + * device). + */ +/**@{**/ + +#ifdef __ASSEMBLER__ +#define _SFR_ASM_COMPAT 1 +#elif !defined(_SFR_ASM_COMPAT) +#define _SFR_ASM_COMPAT 0 +#endif + +#ifndef __ASSEMBLER__ +/* These only work in C programs. */ +#include <inttypes.h> + +#define _MMIO_BYTE(mem_addr) (*(volatile uint8_t *)(mem_addr)) +#define _MMIO_WORD(mem_addr) (*(volatile uint16_t *)(mem_addr)) +#define _MMIO_DWORD(mem_addr) (*(volatile uint32_t *)(mem_addr)) +#endif + +#if _SFR_ASM_COMPAT + +#ifndef __SFR_OFFSET +/* Define as 0 before including this file for compatibility with old asm + sources that don't subtract __SFR_OFFSET from symbolic I/O addresses. */ +# if __AVR_ARCH__ >= 100 +# define __SFR_OFFSET 0x00 +# else +# define __SFR_OFFSET 0x20 +# endif +#endif + +#if (__SFR_OFFSET != 0) && (__SFR_OFFSET != 0x20) +#error "__SFR_OFFSET must be 0 or 0x20" +#endif + +#define _SFR_MEM8(mem_addr) (mem_addr) +#define _SFR_MEM16(mem_addr) (mem_addr) +#define _SFR_MEM32(mem_addr) (mem_addr) +#define _SFR_IO8(io_addr) ((io_addr) + __SFR_OFFSET) +#define _SFR_IO16(io_addr) ((io_addr) + __SFR_OFFSET) + +#define _SFR_IO_ADDR(sfr) ((sfr) - __SFR_OFFSET) +#define _SFR_MEM_ADDR(sfr) (sfr) +#define _SFR_IO_REG_P(sfr) ((sfr) < 0x40 + __SFR_OFFSET) + +#if (__SFR_OFFSET == 0x20) +/* No need to use ?: operator, so works in assembler too. */ +#define _SFR_ADDR(sfr) _SFR_MEM_ADDR(sfr) +#elif !defined(__ASSEMBLER__) +#define _SFR_ADDR(sfr) (_SFR_IO_REG_P(sfr) ? (_SFR_IO_ADDR(sfr) + 0x20) : _SFR_MEM_ADDR(sfr)) +#endif + +#else /* !_SFR_ASM_COMPAT */ + +#ifndef __SFR_OFFSET +# if __AVR_ARCH__ >= 100 +# define __SFR_OFFSET 0x00 +# else +# define __SFR_OFFSET 0x20 +# endif +#endif + +#define _SFR_MEM8(mem_addr) _MMIO_BYTE(mem_addr) +#define _SFR_MEM16(mem_addr) _MMIO_WORD(mem_addr) +#define _SFR_MEM32(mem_addr) _MMIO_DWORD(mem_addr) +#define _SFR_IO8(io_addr) _MMIO_BYTE((io_addr) + __SFR_OFFSET) +#define _SFR_IO16(io_addr) _MMIO_WORD((io_addr) + __SFR_OFFSET) + +#define _SFR_MEM_ADDR(sfr) ((uint16_t) &(sfr)) +#define _SFR_IO_ADDR(sfr) (_SFR_MEM_ADDR(sfr) - __SFR_OFFSET) +#define _SFR_IO_REG_P(sfr) (_SFR_MEM_ADDR(sfr) < 0x40 + __SFR_OFFSET) + +#define _SFR_ADDR(sfr) _SFR_MEM_ADDR(sfr) + +#endif /* !_SFR_ASM_COMPAT */ + +#define _SFR_BYTE(sfr) _MMIO_BYTE(_SFR_ADDR(sfr)) +#define _SFR_WORD(sfr) _MMIO_WORD(_SFR_ADDR(sfr)) +#define _SFR_DWORD(sfr) _MMIO_DWORD(_SFR_ADDR(sfr)) + +/** + * @name Bit Manipulation + */ +/**@{**/ + +/** + * @code #include <avr/io.h> @endcode + * + * Converts a bit number into a byte value. + * + * @note The bit shift is performed by the compiler which then inserts the + * result into the code. Thus, there is no run-time overhead when using + * _BV(). + */ +#define _BV(bit) (1 << (bit)) + +/** @} */ + +#ifndef _VECTOR +#define _VECTOR(N) __vector_ ## N +#endif + +#ifndef __ASSEMBLER__ + + +/** + * @name IO Register Bit Manipulation + */ +/**@{**/ + +/** + * @code #include <avr/io.h> @endcode + * + * Test whether bit @c bit in IO register @c sfr is set. + * This will return a 0 if the bit is clear, and non-zero + * if the bit is set. + */ +#define bit_is_set(sfr, bit) (_SFR_BYTE(sfr) & _BV(bit)) + +/** + * @code #include <avr/io.h> @endcode + * + * Test whether bit @c bit in IO register @c sfr is clear. + * This will return non-zero if the bit is clear, and a 0 + * if the bit is set. + */ + +#define bit_is_clear(sfr, bit) (!(_SFR_BYTE(sfr) & _BV(bit))) + +/** + * @code #include <avr/io.h> @endcode + * + * Wait until bit @c bit in IO register @c sfr is set. + */ +#define loop_until_bit_is_set(sfr, bit) do { } while (bit_is_clear(sfr, bit)) + +/** + * @code #include <avr/io.h> @endcode + * + * Wait until bit @c bit in IO register @c sfr is clear. + */ +#define loop_until_bit_is_clear(sfr, bit) do { } while (bit_is_set(sfr, bit)) + +/** @} */ + +/** @} */ + +#endif /* !__ASSEMBLER__ */ + +#endif /* _SFR_DEFS_H_ */ |