/**
******************************************************************************
* @file CortexM3/BitBand/main.c
* @author MCD Application Team
* @version V3.5.0
* @date 08-April-2011
* @brief Main program body.
******************************************************************************
* @attention
*
* THE PRESENT FIRMWARE WHICH IS FOR GUIDANCE ONLY AIMS AT PROVIDING CUSTOMERS
* WITH CODING INFORMATION REGARDING THEIR PRODUCTS IN ORDER FOR THEM TO SAVE
* TIME. AS A RESULT, STMICROELECTRONICS SHALL NOT BE HELD LIABLE FOR ANY
* DIRECT, INDIRECT OR CONSEQUENTIAL DAMAGES WITH RESPECT TO ANY CLAIMS ARISING
* FROM THE CONTENT OF SUCH FIRMWARE AND/OR THE USE MADE BY CUSTOMERS OF THE
* CODING INFORMATION CONTAINED HEREIN IN CONNECTION WITH THEIR PRODUCTS.
*
*
© COPYRIGHT 2011 STMicroelectronics
******************************************************************************
*/
/* Includes ------------------------------------------------------------------*/
#include "stm32f10x.h"
/** @addtogroup STM32F10x_StdPeriph_Examples
* @{
*/
/** @addtogroup CortexM3_BitBand
* @{
*/
/* Private typedef -----------------------------------------------------------*/
/* Private define ------------------------------------------------------------*/
#define RAM_BASE 0x20000000
#define RAM_BB_BASE 0x22000000
/* Private macro -------------------------------------------------------------*/
#define Var_ResetBit_BB(VarAddr, BitNumber) \
(*(__IO uint32_t *) (RAM_BB_BASE | ((VarAddr - RAM_BASE) << 5) | ((BitNumber) << 2)) = 0)
#define Var_SetBit_BB(VarAddr, BitNumber) \
(*(__IO uint32_t *) (RAM_BB_BASE | ((VarAddr - RAM_BASE) << 5) | ((BitNumber) << 2)) = 1)
#define Var_GetBit_BB(VarAddr, BitNumber) \
(*(__IO uint32_t *) (RAM_BB_BASE | ((VarAddr - RAM_BASE) << 5) | ((BitNumber) << 2)))
/* Private variables ---------------------------------------------------------*/
__IO uint32_t Var, VarAddr = 0, VarBitValue = 0;
/* Private function prototypes -----------------------------------------------*/
/* Private functions ---------------------------------------------------------*/
/**
* @brief Main program.
* @param None
* @retval None
*/
int main(void)
{
/*!< At this stage the microcontroller clock setting is already configured,
this is done through SystemInit() function which is called from startup
file (startup_stm32f10x_xx.s) before to branch to application main.
To reconfigure the default setting of SystemInit() function, refer to
system_stm32f10x.c file
*/
Var = 0x00005AA5;
/* A mapping formula shows how to reference each word in the alias region to a
corresponding bit in the bit-band region. The mapping formula is:
bit_word_addr = bit_band_base + (byte_offset x 32) + (bit_number + 4)
where:
- bit_word_addr: is the address of the word in the alias memory region that
maps to the targeted bit.
- bit_band_base is the starting address of the alias region
- byte_offset is the number of the byte in the bit-band region that contains
the targeted bit
- bit_number is the bit position (0-7) of the targeted bit */
/* Get the variable address --------------------------------------------------*/
VarAddr = (uint32_t)&Var;
/* Modify variable bit using bit-band access ---------------------------------*/
/* Modify Var variable bit 0 -----------------------------------------------*/
Var_ResetBit_BB(VarAddr, 0); /* Var = 0x00005AA4 */
Var_SetBit_BB(VarAddr, 0); /* Var = 0x00005AA5 */
/* Modify Var variable bit 11 ----------------------------------------------*/
Var_ResetBit_BB(VarAddr, 11); /* Var = 0x000052A5 */
/* Get Var variable bit 11 value */
VarBitValue = Var_GetBit_BB(VarAddr, 11); /* VarBitValue = 0x00000000 */
Var_SetBit_BB(VarAddr, 11); /* Var = 0x00005AA5 */
/* Get Var variable bit 11 value */
VarBitValue = Var_GetBit_BB(VarAddr, 11); /* VarBitValue = 0x00000001 */
/* Modify Var variable bit 31 ----------------------------------------------*/
Var_SetBit_BB(VarAddr, 31); /* Var = 0x80005AA5 */
/* Get Var variable bit 31 value */
VarBitValue = Var_GetBit_BB(VarAddr, 31); /* VarBitValue = 0x00000001 */
Var_ResetBit_BB(VarAddr, 31); /* Var = 0x00005AA5 */
/* Get Var variable bit 31 value */
VarBitValue = Var_GetBit_BB(VarAddr, 31); /* VarBitValue = 0x00000000 */
while (1)
{
}
}
#ifdef USE_FULL_ASSERT
/**
* @brief Reports the name of the source file and the source line number
* where the assert_param error has occurred.
* @param file: pointer to the source file name
* @param line: assert_param error line source number
* @retval None
*/
void assert_failed(uint8_t* file, uint32_t line)
{
/* User can add his own implementation to report the file name and line number,
ex: printf("Wrong parameters value: file %s on line %d\r\n", file, line) */
/* Infinite loop */
while (1)
{
}
}
#endif
/**
* @}
*/
/**
* @}
*/
/******************* (C) COPYRIGHT 2011 STMicroelectronics *****END OF FILE****/