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//*****************************************************************************
// +--+
// | ++----+
// +-++ |
// | |
// +-+--+ |
// | +--+--+
// +----+ Copyright (c) 2011 Code Red Technologies Ltd.
//
// Header file containing C macros to provide bitbanding on Cortex-M3 MCU's
//
// Software License Agreement
//
// The software is owned by Code Red Technologies and/or its suppliers, and is
// protected under applicable copyright laws. All rights are reserved. Any
// use in violation of the foregoing restrictions may subject the user to criminal
// sanctions under applicable laws, as well as to civil liability for the breach
// of the terms and conditions of this license.
//
// THIS SOFTWARE IS PROVIDED "AS IS". NO WARRANTIES, WHETHER EXPRESS, IMPLIED
// OR STATUTORY, INCLUDING, BUT NOT LIMITED TO, IMPLIED WARRANTIES OF
// MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE APPLY TO THIS SOFTWARE.
// USE OF THIS SOFTWARE FOR COMMERCIAL DEVELOPMENT AND/OR EDUCATION IS SUBJECT
// TO A CURRENT END USER LICENSE AGREEMENT (COMMERCIAL OR EDUCATIONAL) WITH
// CODE RED TECHNOLOGIES LTD.
//
//*****************************************************************************
#ifndef BITBAND_H_
#define BITBAND_H_
/* The Cortex-M3 memory map includes two bit-band regions. These occupy the lowest
* 1MB of the SRAM and peripheral memory regions respectively.
* + SRAM: Bit-band region: 0x20000000 - 0x20100000
* Bit-band alias: 0x22000000 - 0x23FFFFFF
* + PERI: Bit-band region: 0x40000000 - 0x40100000
* Bit-band alias: 0x42000000 - 0x43FFFFFF
* The mapping formula:
* bit_word_offset = (byte_offset * 32) + (bit_number * 4)
* bit_word_address = bit_band_base + bit_word_offset
* where:
* + bit_word_offset: the position of the target bit in the bit-band memory region
* + bit_word_addr: the address of the word in the alias memory region that maps to the target bit
* + bit_band_base: the starting address of the alias region
* + byte_offset: the number of byte in the bit-band region that contains the targeted bit
* + bit_number: is the bit position (0-7) of the targeted bit
*/
/* Bit band SRAM definitions */
#define BITBAND_SRAM_REF 0x20000000
#define BITBAND_SRAM_BASE 0x22000000
#define BITBAND_SRAM(a,b) ((BITBAND_SRAM_BASE + ((a-BITBAND_SRAM_REF)<<5) + (b<<2))) // Convert SRAM address
/* Bit band PERIPHERAL definitions */
#define BITBAND_PERI_REF 0x40000000
#define BITBAND_PERI_BASE 0x42000000
#define BITBAND_PERI(a,b) ((BITBAND_PERI_BASE + ((a-BITBAND_PERI_REF)<<5) + (b<<2))) // Convert PERI address
/* Basic bit band function definitions */
#define BITBAND_SRAM_ClearBit(a,b) (*(volatile uint32_t *) (BITBAND_SRAM(a,b)) = 0)
#define BITBAND_SRAM_SetBit(a,b) (*(volatile uint32_t *) (BITBAND_SRAM(a,b)) = 1)
#define BITBAND_SRAM_GetBit(a,b) (*(volatile uint32_t *) (BITBAND_SRAM(a,b)))
#define BITBAND_PERI_ClearBit(a,b) (*(volatile uint32_t *) (BITBAND_PERI(a,b)) = 0)
#define BITBAND_PERI_SetBit(a,b) (*(volatile uint32_t *) (BITBAND_PERI(a,b)) = 1)
#define BITBAND_PERI_GetBit(a,b) (*(volatile uint32_t *) (BITBAND_PERI(a,b)))
#endif /* BITBAND_H_ */
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