Detailed Description

Memory Protection Unit (MPU) Peripheral API.

This module contains functions to enable, disable and setup the MPU. The MPU is used to control access attributes and permissions in the memory map. The settings that can be controlled are:

Executable attribute.
Cachable, bufferable and shareable attributes.
Cache policy.
Access permissions: Priviliged or User state, read or write access, and combinations of all these.

The MPU can be activated and deactivated with functions:

*  MPU_Enable(..);
*  MPU_Disable();

The MPU can control 8 memory regions with individual access control settings. Section attributes and permissions are set with:

*  MPU_ConfigureRegion(..);

It is advisable to disable the MPU when altering region settings.

Data Structures
struct	MPU_RegionInit_TypeDef

Macros
#define	MPU_CTRL_HFNMIENA MPU_CTRL_HFNMIENA_Msk

#define	MPU_CTRL_PRIVDEFENA MPU_CTRL_PRIVDEFENA_Msk

#define	MPU_INIT_FLASH_DEFAULT

#define	MPU_INIT_PERIPHERAL_DEFAULT

#define	MPU_INIT_SRAM_DEFAULT

Enumerations
enum	MPU_RegionAp_TypeDef { mpuRegionNoAccess = 0, mpuRegionApPRw = 1, mpuRegionApPRwURo = 2, mpuRegionApFullAccess = 3, mpuRegionApPRo = 5, mpuRegionApPRo_URo = 6 }

enum	MPU_RegionSize_TypeDef { mpuRegionSize32b = 4, mpuRegionSize64b = 5, mpuRegionSize128b = 6, mpuRegionSize256b = 7, mpuRegionSize512b = 8, mpuRegionSize1Kb = 9, mpuRegionSize2Kb = 10, mpuRegionSize4Kb = 11, mpuRegionSize8Kb = 12, mpuRegionSize16Kb = 13, mpuRegionSize32Kb = 14, mpuRegionSize64Kb = 15, mpuRegionSize128Kb = 16, mpuRegionSize256Kb = 17, mpuRegionSize512Kb = 18, mpuRegionSize1Mb = 19, mpuRegionSize2Mb = 20, mpuRegionSize4Mb = 21, mpuRegionSize8Mb = 22, mpuRegionSize16Mb = 23, mpuRegionSize32Mb = 24, mpuRegionSize64Mb = 25, mpuRegionSize128Mb = 26, mpuRegionSize256Mb = 27, mpuRegionSize512Mb = 28, mpuRegionSize1Gb = 29, mpuRegionSize2Gb = 30, mpuRegionSize4Gb = 31 }

Functions
void	MPU_ConfigureRegion (const MPU_RegionInit_TypeDef *init)
	Configure an MPU region. More...

__STATIC_INLINE void	MPU_Disable (void)
	Disable the MPU. More...

__STATIC_INLINE void	MPU_Enable (uint32_t flags)
	Enable the MPU. More...

Macro Definition Documentation

#define MPU_CTRL_HFNMIENA MPU_CTRL_HFNMIENA_Msk

Argument to MPU_enable(). Enables MPU during hard fault, NMI, and FAULTMASK handlers.

Definition at line 65 of file em_mpu.h.

#define MPU_CTRL_PRIVDEFENA MPU_CTRL_PRIVDEFENA_Msk

Argument to MPU_enable(). Enables priviledged access to default memory map.

Definition at line 60 of file em_mpu.h.

#define MPU_INIT_FLASH_DEFAULT

Value:

{                                                             \
  true,                   /* Enable MPU region.            */ \
  0,                      /* MPU Region number.            */ \
  FLASH_MEM_BASE,         /* Flash base address.           */ \
  mpuRegionSize1Mb,       /* Size - Set to max. */            \
  mpuRegionApFullAccess,  /* Access permissions.           */ \
  false,                  /* Execution allowed.            */ \
  false,                  /* Not shareable.                */ \
  true,                   /* Cacheable.                    */ \
  false,                  /* Not bufferable.               */ \
  0,                      /* No subregions.                */ \
  0                       /* No TEX attributes.            */ \
}

Default configuration of MPU region init structure for flash memory.

Definition at line 141 of file em_mpu.h.

#define MPU_INIT_PERIPHERAL_DEFAULT

Value:

{                                                             \
  true,                   /* Enable MPU region.            */ \
  0,                      /* MPU Region number.            */ \
  0,                      /* Region base address.          */ \
  mpuRegionSize32b,       /* Size - Set to minimum         */ \
  mpuRegionApFullAccess,  /* Access permissions.           */ \
  true,                   /* Execution not allowed.        */ \
  true,                   /* Shareable.                    */ \
  false,                  /* Not cacheable.                */ \
  true,                   /* Bufferable.                   */ \
  0,                      /* No subregions.                */ \
  0                       /* No TEX attributes.            */ \
}

Default configuration of MPU region init structure for onchip peripherals.

Definition at line 175 of file em_mpu.h.

#define MPU_INIT_SRAM_DEFAULT

Value:

{                                                             \
  true,                   /* Enable MPU region.            */ \
  1,                      /* MPU Region number.            */ \
  RAM_MEM_BASE,           /* SRAM base address.            */ \
  mpuRegionSize128Kb,     /* Size - Set to max. */            \
  mpuRegionApFullAccess,  /* Access permissions.           */ \
  false,                  /* Execution allowed.            */ \
  true,                   /* Shareable.                    */ \
  true,                   /* Cacheable.                    */ \
  false,                  /* Not bufferable.               */ \
  0,                      /* No subregions.                */ \
  0                       /* No TEX attributes.            */ \
}

Default configuration of MPU region init structure for sram memory.

Definition at line 158 of file em_mpu.h.

Enumeration Type Documentation

enum MPU_RegionAp_TypeDef

MPU region access permission attributes.

Enumerator
mpuRegionNoAccess	No access what so ever.
mpuRegionApPRw	Priviledged state R/W only.
mpuRegionApPRwURo	Priviledged state R/W, User state R only.
mpuRegionApFullAccess	R/W in Priviledged and User state.
mpuRegionApPRo	Priviledged R only.
mpuRegionApPRo_URo	R only in Priviledged and User state.

Definition at line 109 of file em_mpu.h.

enum MPU_RegionSize_TypeDef

Size of an MPU region.

Enumerator
mpuRegionSize32b	32 byte region size.
mpuRegionSize64b	64 byte region size.
mpuRegionSize128b	128 byte region size.
mpuRegionSize256b	256 byte region size.
mpuRegionSize512b	512 byte region size.
mpuRegionSize1Kb	1K byte region size.
mpuRegionSize2Kb	2K byte region size.
mpuRegionSize4Kb	4K byte region size.
mpuRegionSize8Kb	8K byte region size.
mpuRegionSize16Kb	16K byte region size.
mpuRegionSize32Kb	32K byte region size.
mpuRegionSize64Kb	64K byte region size.
mpuRegionSize128Kb	128K byte region size.
mpuRegionSize256Kb	256K byte region size.
mpuRegionSize512Kb	512K byte region size.
mpuRegionSize1Mb	1M byte region size.
mpuRegionSize2Mb	2M byte region size.
mpuRegionSize4Mb	4M byte region size.
mpuRegionSize8Mb	8M byte region size.
mpuRegionSize16Mb	16M byte region size.
mpuRegionSize32Mb	32M byte region size.
mpuRegionSize64Mb	64M byte region size.
mpuRegionSize128Mb	128M byte region size.
mpuRegionSize256Mb	256M byte region size.
mpuRegionSize512Mb	512M byte region size.
mpuRegionSize1Gb	1G byte region size.
mpuRegionSize2Gb	2G byte region size.
mpuRegionSize4Gb	4G byte region size.

Definition at line 74 of file em_mpu.h.

Function Documentation

void MPU_ConfigureRegion ( const MPU_RegionInit_TypeDef * init )

Configure an MPU region.

Writes to MPU RBAR and RASR registers. Refer to Cortex-M3 Reference Manual, MPU chapter for further details. To disable a region it is only required to set init->regionNo to the desired value and init->regionEnable = false.

Parameters

[in] init Pointer to a structure containing MPU region init information.

Definition at line 91 of file em_mpu.c.

References MPU_RegionInit_TypeDef::accessPermission, MPU_RegionInit_TypeDef::baseAddress, MPU_RegionInit_TypeDef::bufferable, MPU_RegionInit_TypeDef::cacheable, MPU_RegionInit_TypeDef::disableExec, MPU_RegionInit_TypeDef::regionEnable, MPU_RegionInit_TypeDef::regionNo, MPU_RegionInit_TypeDef::shareable, MPU_RegionInit_TypeDef::size, MPU_RegionInit_TypeDef::srd, and MPU_RegionInit_TypeDef::tex.

__STATIC_INLINE void MPU_Disable ( void )

Disable the MPU.

Disable MPU and MPU fault exceptions.

Definition at line 205 of file em_mpu.h.

__STATIC_INLINE void MPU_Enable ( uint32_t flags )

Enable the MPU.

Enable MPU and MPU fault exceptions.

Parameters

[in] flags Use a logical OR of MPU_CTRL_PRIVDEFENA and MPU_CTRL_HFNMIENA as needed.

Definition at line 221 of file em_mpu.h.

Detailed Description

Data Structures

Macros

Enumerations

Functions

Macro Definition Documentation

Enumeration Type Documentation

Function Documentation