Overview

The MPU driver provides hardware access control for all memory references generated in the device. Use the MPU driver to program the region descriptors that define memory spaces and their access rights. After initialization, the MPU concurrently monitors the system bus transactions and evaluates the appropriateness.

Initialization and Deinitialize

To initialize the MPU module, call the MPU_Init() function and provide the user configuration data structure. This function sets the configuration of the MPU module automatically and enables the MPU module.
Note that the configuration start address, end address, the region valid value, and the debugger's access permission for the MPU region 0 cannot be changed.

This is example code to configure the MPU driver:

 // Defines the MPU memory access permission configuration structure . //
  mpu_rwxrights_master_access_control_t mpuRwxAccessRightsMasters =
 {
      kMPU_SupervisorReadWriteExecute, 
      kMPU_UserNoAccessRights,         
      kMPU_IdentifierDisable,          
      kMPU_SupervisorEqualToUsermode,  
      kMPU_UserNoAccessRights,         
      kMPU_IdentifierDisable,          
      kMPU_SupervisorEqualToUsermode,  
      kMPU_UserNoAccessRights,         
      kMPU_IdentifierDisable,          
      kMPU_SupervisorEqualToUsermode,  
      kMPU_UserNoAccessRights,         
      kMPU_IdentifierDisable           
 }
  mpu_rwrights_master_access_control_t mpuRwAccessRightsMasters =
 {
       false,              
       false,              
       false,              
       false,              
       false,              
       false,              
       false,              
       false               
};
 // Defines the MPU region configuration structure. //
  mpu_region_config_t mpuRegionConfig =
 {
      0,                      
      0x0,                    
      0xffffffff,             
      mpuRwxAccessRightsMasters,     
      mpuRwAccessRightsMasters,    
      0,
      0
};
 // Defines the MPU user configuration structure. //
  mpu_config_t mpuUserConfig =
 {
      mpuRegionConfig,   
      NULL               
 };
 // Initializes the MPU region 0. //
 MPU_Init(MPU, &mpuUserConfig);

Basic Control Operations

MPU can be enabled/disabled for the entire memory protection region by calling the MPU_Enable(). To save the power for any unused special regions when the entire memory protection region is disabled, call the MPU_RegionEnable().

After MPU initialization, the MPU_SetRegionLowMasterAccessRights() and MPU_SetRegionHighMasterAccessRights() can be used to change the access rights for special master ports and for special region numbers. The MPU_SetRegionConfig can be used to set the whole region with the start/end address with access rights.

The MPU_GetHardwareInfo() API is provided to get the hardware information for the device. The MPU_GetSlavePortErrorStatus() API is provided to get the error status of a special slave port. When an error happens in this port, the MPU_GetDetailErrorAccessInfo() API is provided to get the detailed error information.

Data Structures
struct	mpu_hardware_info_t
	MPU hardware basic information. More...

struct	mpu_access_err_info_t
	MPU detail error access information. More...

struct	mpu_rwxrights_master_access_control_t
	MPU read/write/execute rights control for bus master 0 ~ 3. More...

struct	mpu_rwrights_master_access_control_t
	MPU read/write access control for bus master 4 ~ 7. More...

struct	mpu_region_config_t
	MPU region configuration structure. More...

struct	mpu_config_t
	The configuration structure for the MPU initialization. More...

Macros
#define	MPU_REGION_RWXRIGHTS_MASTER_SHIFT(n) (n * 6)
	MPU the bit shift for masters with privilege rights: read write and execute. More...

#define	MPU_REGION_RWXRIGHTS_MASTER_MASK(n) (0x1Fu << MPU_REGION_RWXRIGHTS_MASTER_SHIFT(n))
	MPU masters with read, write and execute rights bit mask. More...

#define	MPU_REGION_RWXRIGHTS_MASTER_WIDTH 5
	MPU masters with read, write and execute rights bit width. More...

#define	MPU_REGION_RWXRIGHTS_MASTER(n, x) (((uint32_t)(((uint32_t)(x)) << MPU_REGION_RWXRIGHTS_MASTER_SHIFT(n))) & MPU_REGION_RWXRIGHTS_MASTER_MASK(n))
	MPU masters with read, write and execute rights priority setting. More...

#define	MPU_REGION_RWXRIGHTS_MASTER_PE_SHIFT(n) (n * 6 + MPU_REGION_RWXRIGHTS_MASTER_WIDTH)
	MPU masters with read, write and execute rights process enable bit shift. More...

#define	MPU_REGION_RWXRIGHTS_MASTER_PE_MASK(n) (0x1u << MPU_REGION_RWXRIGHTS_MASTER_PE_SHIFT(n))
	MPU masters with read, write and execute rights process enable bit mask. More...

#define	MPU_REGION_RWXRIGHTS_MASTER_PE(n, x) (((uint32_t)(((uint32_t)(x)) << MPU_REGION_RWXRIGHTS_MASTER_PE_SHIFT(n))) & MPU_REGION_RWXRIGHTS_MASTER_PE_MASK(n))
	MPU masters with read, write and execute rights process enable setting. More...

#define	MPU_REGION_RWRIGHTS_MASTER_SHIFT(n) ((n - FSL_FEATURE_MPU_PRIVILEGED_RIGHTS_MASTER_COUNT) * 2 + 24)
	MPU masters with normal read write permission bit shift. More...

#define	MPU_REGION_RWRIGHTS_MASTER_MASK(n) (0x3u << MPU_REGION_RWRIGHTS_MASTER_SHIFT(n))
	MPU masters with normal read write rights bit mask. More...

#define	MPU_REGION_RWRIGHTS_MASTER(n, x) (((uint32_t)(((uint32_t)(x)) << MPU_REGION_RWRIGHTS_MASTER_SHIFT(n))) & MPU_REGION_RWRIGHTS_MASTER_MASK(n))
	MPU masters with normal read write rights priority setting. More...

Enumerations
enum	mpu_region_total_num_t { kMPU_8Regions = 0x0U, kMPU_12Regions = 0x1U, kMPU_16Regions = 0x2U }
	Describes the number of MPU regions. More...

enum	mpu_slave_t { kMPU_Slave0 = 4U, kMPU_Slave1 = 3U, kMPU_Slave2 = 2U, kMPU_Slave3 = 1U, kMPU_Slave4 = 0U }
	MPU slave port number. More...

enum	mpu_err_access_control_t { kMPU_NoRegionHit = 0U, kMPU_NoneOverlappRegion = 1U, kMPU_OverlappRegion = 2U }
	MPU error access control detail. More...

enum	mpu_err_access_type_t { kMPU_ErrTypeRead = 0U, kMPU_ErrTypeWrite = 1U }
	MPU error access type. More...

enum	mpu_err_attributes_t { kMPU_InstructionAccessInUserMode = 0U, kMPU_DataAccessInUserMode = 1U, kMPU_InstructionAccessInSupervisorMode = 2U, kMPU_DataAccessInSupervisorMode = 3U }
	MPU access error attributes. More...

enum	mpu_supervisor_access_rights_t { kMPU_SupervisorReadWriteExecute = 0U, kMPU_SupervisorReadExecute = 1U, kMPU_SupervisorReadWrite = 2U, kMPU_SupervisorEqualToUsermode = 3U }
	MPU access rights in supervisor mode for bus master 0 ~ 3. More...

enum	mpu_user_access_rights_t { kMPU_UserNoAccessRights = 0U, kMPU_UserExecute = 1U, kMPU_UserWrite = 2U, kMPU_UserWriteExecute = 3U, kMPU_UserRead = 4U, kMPU_UserReadExecute = 5U, kMPU_UserReadWrite = 6U, kMPU_UserReadWriteExecute = 7U }
	MPU access rights in user mode for bus master 0 ~ 3. More...

Driver version
#define	FSL_MPU_DRIVER_VERSION (MAKE_VERSION(2, 1, 0))
	MPU driver version 2.1.0. More...

Initialization and deinitialization
void	MPU_Init (MPU_Type base, const mpu_config_t config)
	Initializes the MPU with the user configuration structure. More...

void	MPU_Deinit (MPU_Type *base)
	Deinitializes the MPU regions. More...

Basic Control Operations
static void	MPU_Enable (MPU_Type *base, bool enable)
	Enables/disables the MPU globally. More...

static void	MPU_RegionEnable (MPU_Type *base, uint32_t number, bool enable)
	Enables/disables the MPU for a special region. More...

void	MPU_GetHardwareInfo (MPU_Type base, mpu_hardware_info_t hardwareInform)
	Gets the MPU basic hardware information. More...

void	MPU_SetRegionConfig (MPU_Type base, const mpu_region_config_t regionConfig)
	Sets the MPU region. More...

void	MPU_SetRegionAddr (MPU_Type *base, uint32_t regionNum, uint32_t startAddr, uint32_t endAddr)
	Sets the region start and end address. More...

void	MPU_SetRegionRwxMasterAccessRights (MPU_Type base, uint32_t regionNum, uint32_t masterNum, const mpu_rwxrights_master_access_control_t accessRights)
	Sets the MPU region access rights for masters with read, write and execute rights. More...

void	MPU_SetRegionRwMasterAccessRights (MPU_Type base, uint32_t regionNum, uint32_t masterNum, const mpu_rwrights_master_access_control_t accessRights)
	Sets the MPU region access rights for masters with read and write rights. More...

bool	MPU_GetSlavePortErrorStatus (MPU_Type *base, mpu_slave_t slaveNum)
	Gets the numbers of slave ports where errors occur. More...

void	MPU_GetDetailErrorAccessInfo (MPU_Type base, mpu_slave_t slaveNum, mpu_access_err_info_t errInform)
	Gets the MPU detailed error access information. More...

Data Structure Documentation

struct mpu_hardware_info_t

Data Fields
uint8_t	hardwareRevisionLevel
	Specifies the MPU's hardware and definition reversion level. More...

uint8_t	slavePortsNumbers
	Specifies the number of slave ports connected to MPU. More...

mpu_region_total_num_t	regionsNumbers
	Indicates the number of region descriptors implemented. More...

Field Documentation

uint8_t mpu_hardware_info_t::hardwareRevisionLevel

uint8_t mpu_hardware_info_t::slavePortsNumbers

mpu_region_total_num_t mpu_hardware_info_t::regionsNumbers

struct mpu_access_err_info_t

Data Fields
uint32_t	master
	Access error master. More...

mpu_err_attributes_t	attributes
	Access error attributes. More...

mpu_err_access_type_t	accessType
	Access error type. More...

mpu_err_access_control_t	accessControl
	Access error control. More...

uint32_t	address
	Access error address. More...

Field Documentation

uint32_t mpu_access_err_info_t::master

mpu_err_attributes_t mpu_access_err_info_t::attributes

mpu_err_access_type_t mpu_access_err_info_t::accessType

mpu_err_access_control_t mpu_access_err_info_t::accessControl

uint32_t mpu_access_err_info_t::address

struct mpu_rwxrights_master_access_control_t

Data Fields
mpu_supervisor_access_rights_t	superAccessRights
	Master access rights in supervisor mode. More...

mpu_user_access_rights_t	userAccessRights
	Master access rights in user mode. More...

Field Documentation

mpu_supervisor_access_rights_t mpu_rwxrights_master_access_control_t::superAccessRights

mpu_user_access_rights_t mpu_rwxrights_master_access_control_t::userAccessRights

struct mpu_rwrights_master_access_control_t

Data Fields
bool	writeEnable
	Enables or disables write permission. More...

bool	readEnable
	Enables or disables read permission. More...

Field Documentation

bool mpu_rwrights_master_access_control_t::writeEnable

bool mpu_rwrights_master_access_control_t::readEnable

struct mpu_region_config_t

This structure is used to configure the regionNum region. The accessRights1[0] ~ accessRights1[3] are used to configure the bus master 0 ~ 3 with the privilege rights setting. The accessRights2[0] ~ accessRights2[3] are used to configure the high master 4 ~ 7 with the normal read write permission. The master port assignment is the chip configuration. Normally, the core is the master 0, debugger is the master 1. Note: MPU assigns a priority scheme where the debugger is treated as the highest priority master followed by the core and then all the remaining masters. MPU protection does not allow writes from the core to affect the "regionNum 0" start and end address nor the permissions associated with the debugger. It can only write the permission fields associated with the other masters. This protection guarantee the debugger always has access to the entire address space and those rights can't be changed by the core or any other bus master. Prepare the region configuration when regionNum is 0.

Data Fields
uint32_t	regionNum
	MPU region number, range form 0 ~ FSL_FEATURE_MPU_DESCRIPTOR_COUNT - 1. More...

uint32_t	startAddress
	Memory region start address. More...

uint32_t	endAddress
	Memory region end address. More...

mpu_rwxrights_master_access_control_t	accessRights1 [4]
	Masters with read, write and execute rights setting. More...

mpu_rwrights_master_access_control_t	accessRights2 [4]
	Masters with normal read write rights setting. More...

Field Documentation

uint32_t mpu_region_config_t::regionNum

uint32_t mpu_region_config_t::startAddress

Note: bit0 ~ bit4 always be marked as 0 by MPU. The actual start address is 0-modulo-32 byte address.

uint32_t mpu_region_config_t::endAddress

Note: bit0 ~ bit4 always be marked as 1 by MPU. The actual end address is 31-modulo-32 byte address.

mpu_rwxrights_master_access_control_t mpu_region_config_t::accessRights1[4]

mpu_rwrights_master_access_control_t mpu_region_config_t::accessRights2[4]

struct mpu_config_t

This structure is used when calling the MPU_Init function.

Data Fields
mpu_region_config_t	regionConfig
	region access permission. More...

struct _mpu_config *	next
	pointer to the next structure. More...

Field Documentation

mpu_region_config_t mpu_config_t::regionConfig

struct _mpu_config* mpu_config_t::next

Macro Definition Documentation

#define FSL_MPU_DRIVER_VERSION (MAKE_VERSION(2, 1, 0))

#define MPU_REGION_RWXRIGHTS_MASTER_SHIFT ( n ) (n * 6)

#define MPU_REGION_RWXRIGHTS_MASTER_MASK ( n ) (0x1Fu << MPU_REGION_RWXRIGHTS_MASTER_SHIFT(n))

#define MPU_REGION_RWXRIGHTS_MASTER_WIDTH 5

#define MPU_REGION_RWXRIGHTS_MASTER	(	n,
		x
	)	(((uint32_t)(((uint32_t)(x)) << MPU_REGION_RWXRIGHTS_MASTER_SHIFT(n))) & MPU_REGION_RWXRIGHTS_MASTER_MASK(n))

#define MPU_REGION_RWXRIGHTS_MASTER_PE_SHIFT ( n ) (n * 6 + MPU_REGION_RWXRIGHTS_MASTER_WIDTH)

#define MPU_REGION_RWXRIGHTS_MASTER_PE_MASK ( n ) (0x1u << MPU_REGION_RWXRIGHTS_MASTER_PE_SHIFT(n))

#define MPU_REGION_RWXRIGHTS_MASTER_PE	(	n,
		x
	)	(((uint32_t)(((uint32_t)(x)) << MPU_REGION_RWXRIGHTS_MASTER_PE_SHIFT(n))) & MPU_REGION_RWXRIGHTS_MASTER_PE_MASK(n))

#define MPU_REGION_RWRIGHTS_MASTER_SHIFT ( n ) ((n - FSL_FEATURE_MPU_PRIVILEGED_RIGHTS_MASTER_COUNT) * 2 + 24)

#define MPU_REGION_RWRIGHTS_MASTER_MASK ( n ) (0x3u << MPU_REGION_RWRIGHTS_MASTER_SHIFT(n))

#define MPU_REGION_RWRIGHTS_MASTER	(	n,
		x
	)	(((uint32_t)(((uint32_t)(x)) << MPU_REGION_RWRIGHTS_MASTER_SHIFT(n))) & MPU_REGION_RWRIGHTS_MASTER_MASK(n))

Enumeration Type Documentation

enum mpu_region_total_num_t

Enumerator
kMPU_8Regions	MPU supports 8 regions.
kMPU_12Regions	MPU supports 12 regions.
kMPU_16Regions	MPU supports 16 regions.

enum mpu_slave_t

Enumerator
kMPU_Slave0	MPU slave port 0.
kMPU_Slave1	MPU slave port 1.
kMPU_Slave2	MPU slave port 2.
kMPU_Slave3	MPU slave port 3.
kMPU_Slave4	MPU slave port 4.

enum mpu_err_access_control_t

Enumerator
kMPU_NoRegionHit	No region hit error.
kMPU_NoneOverlappRegion	Access single region error.
kMPU_OverlappRegion	Access overlapping region error.

enum mpu_err_access_type_t

Enumerator
kMPU_ErrTypeRead	MPU error access type — read.
kMPU_ErrTypeWrite	MPU error access type — write.

enum mpu_err_attributes_t

Enumerator
kMPU_InstructionAccessInUserMode	Access instruction error in user mode.
kMPU_DataAccessInUserMode	Access data error in user mode.
kMPU_InstructionAccessInSupervisorMode	Access instruction error in supervisor mode.
kMPU_DataAccessInSupervisorMode	Access data error in supervisor mode.

enum mpu_supervisor_access_rights_t

Enumerator
kMPU_SupervisorReadWriteExecute	Read write and execute operations are allowed in supervisor mode.
kMPU_SupervisorReadExecute	Read and execute operations are allowed in supervisor mode.
kMPU_SupervisorReadWrite	Read write operations are allowed in supervisor mode.
kMPU_SupervisorEqualToUsermode	Access permission equal to user mode.

enum mpu_user_access_rights_t

Enumerator
kMPU_UserNoAccessRights	No access allowed in user mode.
kMPU_UserExecute	Execute operation is allowed in user mode.
kMPU_UserWrite	Write operation is allowed in user mode.
kMPU_UserWriteExecute	Write and execute operations are allowed in user mode.
kMPU_UserRead	Read is allowed in user mode.
kMPU_UserReadExecute	Read and execute operations are allowed in user mode.
kMPU_UserReadWrite	Read and write operations are allowed in user mode.
kMPU_UserReadWriteExecute	Read write and execute operations are allowed in user mode.

Function Documentation

void MPU_Init	(	MPU_Type *	base,
		const mpu_config_t *	config
	)

This function configures the MPU module with the user-defined configuration.

Parameters

base	MPU peripheral base address.
config	The pointer to the configuration structure.

void MPU_Deinit ( MPU_Type * base )

Parameters

base	MPU peripheral base address.

static void MPU_Enable	(	MPU_Type *	base,
		bool	enable
	)

inlinestatic

Call this API to enable or disable the MPU module.

Parameters

base	MPU peripheral base address.
enable	True enable MPU, false disable MPU.

static void MPU_RegionEnable	(	MPU_Type *	base,
		uint32_t	number,
		bool	enable
	)

inlinestatic

When MPU is enabled, call this API to disable an unused region of an enabled MPU. Call this API to minimize the power dissipation.

Parameters

base	MPU peripheral base address.
number	MPU region number.
enable	True enable the special region MPU, false disable the special region MPU.

void MPU_GetHardwareInfo	(	MPU_Type *	base,
		mpu_hardware_info_t *	hardwareInform
	)

Parameters

base	MPU peripheral base address.
hardwareInform	The pointer to the MPU hardware information structure. See "mpu_hardware_info_t".

void MPU_SetRegionConfig	(	MPU_Type *	base,
		const mpu_region_config_t *	regionConfig
	)

Note: Due to the MPU protection, the Region number 0 does not allow writes from core to affect the start and end address nor the permissions associated with the debugger. It can only write the permission fields associated with the other masters.

Parameters

base	MPU peripheral base address.
regionConfig	The pointer to the MPU user configuration structure. See "mpu_region_config_t".

void MPU_SetRegionAddr	(	MPU_Type *	base,
		uint32_t	regionNum,
		uint32_t	startAddr,
		uint32_t	endAddr
	)

Memory region start address. Note: bit0 ~ bit4 is always marked as 0 by MPU. The actual start address by MPU is 0-modulo-32 byte address. Memory region end address. Note: bit0 ~ bit4 always be marked as 1 by MPU. The actual end address used by MPU is 31-modulo-32 byte address. Note: Due to the MPU protection, the startAddr and endAddr can't be changed by the core when regionNum is 0.

Parameters

base	MPU peripheral base address.
regionNum	MPU region number. The range is from 0 to FSL_FEATURE_MPU_DESCRIPTOR_COUNT - 1.
startAddr	Region start address.
endAddr	Region end address.

void MPU_SetRegionRwxMasterAccessRights	(	MPU_Type *	base,
		uint32_t	regionNum,
		uint32_t	masterNum,
		const mpu_rwxrights_master_access_control_t *	accessRights
	)

The MPU access rights depend on two board classifications of bus masters. The privilege rights masters and the normal rights masters. The privilege rights masters have the read, write and execute access rights. So except the normal read and write rights, the execute rights is also allowed for these masters. The privilege rights masters are normally range from bus masters 0 - 3. However, the maximum master number is device-specific. See the "FSL_FEATURE_MPU_PRIVILEGED_RIGHTS_MASTER_MAX_INDEX". The normal rights masters access rights control see "MPU_SetRegionRwMasterAccessRights()".

Parameters

base	MPU peripheral base address.
regionNum	MPU region number. Should range from 0 to FSL_FEATURE_MPU_DESCRIPTOR_COUNT - 1.
masterNum	MPU bus master number. Should range from 0 to FSL_FEATURE_MPU_PRIVILEGED_RIGHTS_MASTER_MAX_INDEX.
accessRights	The pointer to the MPU access rights configuration. See "mpu_rwxrights_master_access_control_t".

void MPU_SetRegionRwMasterAccessRights	(	MPU_Type *	base,
		uint32_t	regionNum,
		uint32_t	masterNum,
		const mpu_rwrights_master_access_control_t *	accessRights
	)

The MPU access rights depend on two board classifications of bus masters. The privilege rights masters and the normal rights masters. The normal rights masters only have the read and write access permissions. The privilege rights access control see "MPU_SetRegionRwxMasterAccessRights".

Parameters

base	MPU peripheral base address.
regionNum	MPU region number. The range is from 0 to FSL_FEATURE_MPU_DESCRIPTOR_COUNT - 1.
masterNum	MPU bus master number. Should range from FSL_FEATURE_MPU_PRIVILEGED_RIGHTS_MASTER_COUNT to ~ FSL_FEATURE_MPU_MASTER_MAX_INDEX.
accessRights	The pointer to the MPU access rights configuration. See "mpu_rwrights_master_access_control_t".

bool MPU_GetSlavePortErrorStatus	(	MPU_Type *	base,
		mpu_slave_t	slaveNum
	)

Parameters

base	MPU peripheral base address.
slaveNum	MPU slave port number.

Returns: The slave ports error status. true - error happens in this slave port. false - error didn't happen in this slave port.

void MPU_GetDetailErrorAccessInfo	(	MPU_Type *	base,
		mpu_slave_t	slaveNum,
		mpu_access_err_info_t *	errInform
	)

Parameters

base	MPU peripheral base address.
slaveNum	MPU slave port number.
errInform	The pointer to the MPU access error information. See "mpu_access_err_info_t".

Overview

Initialization and Deinitialize

Basic Control Operations

Data Structures

Macros

Enumerations

Driver version

Initialization and deinitialization

Basic Control Operations

Data Structure Documentation

Data Fields

Field Documentation

Data Fields

Field Documentation

Data Fields

Field Documentation

Data Fields

Field Documentation

Data Fields

Field Documentation

Data Fields

Field Documentation

Macro Definition Documentation

Enumeration Type Documentation

Function Documentation