Description

Memory System Controller API.

Contains functions to control the MSC, primarily the Flash. Users can perform Flash memory write and erase operations, as well as optimization of the CPU instruction fetch interface for the application. Available instruction fetch features depends on the MCU or SoC family, but features such as instruction pre-fetch, cache, and configurable branch prediction are typically available.

Note: Flash wait-state configuration is handled by CMU - Clock Management Unit. When core clock configuration is changed by a call to functions such as CMU_ClockSelectSet() or CMU_HFRCOBandSet(), then Flash wait-state configuration is also updated.

MSC resets into a safe state. To initialize the instruction interface to recommended settings:

MSC_ExecConfig_TypeDef execConfig = MSC_EXECCONFIG_DEFAULT;

MSC_ExecConfigSet(&execConfig);

Note: The optimal configuration is highly application dependent. Performance benchmarking is supported by most families. See MSC_StartCacheMeasurement() and MSC_GetCacheMeasurement() for more details.; The flash write and erase runs from RAM on the EFM32G devices. On all other devices the flash write and erase functions run from flash.; Flash erase may add ms of delay to interrupt latency if executing from Flash.

Flash write and erase operations are supported by MSC_WriteWord(), MSC_ErasePage(), and MSC_MassErase(). Mass erase is supported for MCU and SoC families with larger Flash sizes.

Note: MSC_Init() must be called prior to any Flash write or erase operation.

The following steps are necessary to perform a page erase and write:

uint32_t * userDataPage = (uint32_t *) USERDATA_BASE;
uint32_t userData[] = {
  0x01020304,
  0x05060708
};
MSC_ErasePage(userDataPage);
MSC_WriteWord(userDataPage, userData, sizeof(userData));

Note: The configuration EM_MSC_RUN_FROM_RAM is used for allocating the flash write functions in FLASH and RAM respectively. By default, flash write functions are placed in RAM on EFM32G and Series 2 devices automatically and that could not be changed. For other devices, flash write functions are placed in FLASH but that could be changed using EM_MSC_RUN_FROM_RAM.

Data Structures
struct	MSC_ExecConfig_TypeDef
	Code execution configuration.

Functions
bool	MSC_LockGetLocked (void)
	Get the status of the MSC register lock.

void	MSC_LockSetLocked (void)
	Set the MSC register lock to a locked state.

void	MSC_LockSetUnlocked (void)
	Set the MSC register lock to an unlocked state.

uint32_t	MSC_ReadCTRLGet (void)
	Get the current value of the read control register (MSC_READCTRL).

void	MSC_ReadCTRLSet (uint32_t value)
	Write a value to the read control register (MSC_READCTRL).

void	MSC_IntClear (uint32_t flags)
	Clear one or more pending MSC interrupts.

void	MSC_IntDisable (uint32_t flags)
	Disable one or more MSC interrupts.

void	MSC_IntEnable (uint32_t flags)
	Enable one or more MSC interrupts.

uint32_t	MSC_IntGet (void)
	Get pending MSC interrupt flags.

uint32_t	MSC_IntGetEnabled (void)
	Get enabled and pending MSC interrupt flags.

void	MSC_IntSet (uint32_t flags)
	Set one or more pending MSC interrupts from SW.

void	MSC_StartCacheMeasurement (void)
	Start measuring the cache hit ratio.

int32_t	MSC_GetCacheMeasurement (void)
	Stop measuring the hit rate.

void	MSC_FlushCache (void)
	Flush contents of instruction cache.

void	MSC_EnableCache (bool enable)
	Enable or disable instruction cache functionality.

void	MSC_EnableCacheIRQs (bool enable)
	Enable or disable instruction cache functionality in IRQs.

void	MSC_EnableAutoCacheFlush (bool enable)
	Enable or disable instruction cache flushing when writing to flash.

void	MSC_ExecConfigSet (MSC_ExecConfig_TypeDef *execConfig)
	Set the MSC code execution configuration.

MSC_RAMFUNC_DECLARATOR MSC_Status_TypeDef	MSC_WriteWordFast (uint32_t address, void const data, uint32_t numBytes)
	Writes data to flash memory.

SL_RAMFUNC_DECLARATOR MSC_Status_TypeDef	MSC_MassErase (void)
	Erase the entire Flash in one operation.

MSC_RAMFUNC_DECLARATOR MSC_Status_TypeDef	MSC_ErasePage (uint32_t *startAddress)
	Erases a page in flash memory.

MSC_RAMFUNC_DECLARATOR MSC_Status_TypeDef	MSC_WriteWord (uint32_t address, void const data, uint32_t numBytes)
	Writes data to flash memory.

MSC_Status_TypeDef	MSC_WriteWordDma (int ch, uint32_t address, const void data, uint32_t numBytes)
	Writes data from RAM to flash memory using the DMA.

void	MSC_Init (void)
	Enables the flash controller for writing.

void	MSC_Deinit (void)
	Disables the flash controller for writing.

Macros
#define	MSC_PROGRAM_TIMEOUT 10000000UL
	Timeout used while waiting for Flash to become ready after a write.

#define	MSC_EXECCONFIG_DEFAULT
	Default MSC ExecConfig initialization.

Enumerations
enum	MSC_Status_TypeDef { mscReturnOk = 0, mscReturnInvalidAddr = -1, mscReturnLocked = -2, mscReturnTimeOut = -3, mscReturnUnaligned = -4 }
	Return codes for writing/erasing Flash.

Function Documentation

◆ MSC_LockGetLocked()

bool MSC_LockGetLocked ( void )

inline

Get the status of the MSC register lock.

Returns: Boolean true if register lock is applied, false otherwise.

◆ MSC_LockSetLocked()

void MSC_LockSetLocked ( void )

inline

Set the MSC register lock to a locked state.

◆ MSC_LockSetUnlocked()

void MSC_LockSetUnlocked ( void )

inline

Set the MSC register lock to an unlocked state.

◆ MSC_ReadCTRLGet()

uint32_t MSC_ReadCTRLGet ( void )

inline

Get the current value of the read control register (MSC_READCTRL).

Returns: The 32-bit value read from the MSC_READCTRL register.

◆ MSC_ReadCTRLSet()

void MSC_ReadCTRLSet ( uint32_t value )

inline

Write a value to the read control register (MSC_READCTRL).

Parameters

[in] value The 32-bit value to write to the MSC_READCTRL register.

◆ MSC_IntClear()

void MSC_IntClear ( uint32_t flags )

inline

Clear one or more pending MSC interrupts.

Parameters

[in] flags Pending MSC interrupt source to clear. Use a bitwise logic OR combination of valid interrupt flags for the MSC module (MSC_IF_nnn).

◆ MSC_IntDisable()

void MSC_IntDisable ( uint32_t flags )

inline

Disable one or more MSC interrupts.

Parameters

[in] flags MSC interrupt sources to disable. Use a bitwise logic OR combination of valid interrupt flags for the MSC module (MSC_IF_nnn).

◆ MSC_IntEnable()

void MSC_IntEnable ( uint32_t flags )

inline

Enable one or more MSC interrupts.

Note: Depending on the use, a pending interrupt may already be set prior to enabling the interrupt. To ignore a pending interrupt, consider using MSC_IntClear() prior to enabling the interrupt.

Parameters

[in] flags MSC interrupt sources to enable. Use a bitwise logic OR combination of valid interrupt flags for the MSC module (MSC_IF_nnn).

◆ MSC_IntGet()

uint32_t MSC_IntGet ( void )

inline

Get pending MSC interrupt flags.

Note: The event bits are not cleared by the use of this function.

Returns: MSC interrupt sources pending. A bitwise logic OR combination of valid interrupt flags for the MSC module (MSC_IF_nnn).

◆ MSC_IntGetEnabled()

uint32_t MSC_IntGetEnabled ( void )

inline

Get enabled and pending MSC interrupt flags.

Useful for handling more interrupt sources in the same interrupt handler.

Note: Interrupt flags are not cleared by the use of this function.

Returns

Pending and enabled MSC interrupt sources. The return value is the bitwise AND of

the enabled interrupt sources in MSC_IEN and
the pending interrupt flags MSC_IF

◆ MSC_IntSet()

void MSC_IntSet ( uint32_t flags )

inline

Set one or more pending MSC interrupts from SW.

Parameters

[in] flags MSC interrupt sources to set to pending. Use a bitwise logic OR combination of valid interrupt flags for the MSC module (MSC_IF_nnn).

◆ MSC_StartCacheMeasurement()

void MSC_StartCacheMeasurement ( void )

inline

Start measuring the cache hit ratio.

Starts performance counters. It is defined inline to minimize the impact of this code on the measurement itself.

◆ MSC_GetCacheMeasurement()

int32_t MSC_GetCacheMeasurement ( void )

inline

Stop measuring the hit rate.

Note

Defined inline to minimize the impact of this code on the measurement itself. Only works for relatively short sections of code. To measure longer sections of code, implement an IRQ Handler for the CHOF and CMOF overflow interrupts. These overflows need to be counted and included in the total. Functions can then be implemented as follows:

* volatile uint32_t hitOverflows
* volatile uint32_t missOverflows
*
* void MSC_IRQHandler(void)
* {
*   uint32_t flags;
*   flags = MSC->IF;
*   if (flags & MSC_IF_CHOF) {
*      MSC->IFC = MSC_IF_CHOF;
*      hitOverflows++;
*   }
*   if (flags & MSC_IF_CMOF) {
*     MSC->IFC = MSC_IF_CMOF;
*     missOverflows++;
*   }
* }
*
* void startPerformanceCounters(void)
* {
*   hitOverflows = 0;
*   missOverflows = 0;
*
*   MSC_IntEnable(MSC_IF_CHOF | MSC_IF_CMOF);
*   NVIC_EnableIRQ(MSC_IRQn);
*
*   MSC_StartCacheMeasurement();
* }
*

Returns: Returns -1 if there has been no cache accesses. Returns -2 if there has been an overflow in the performance counters. If not, it will return the percentage of hits versus misses.

◆ MSC_FlushCache()

void MSC_FlushCache ( void )

inline

Flush contents of instruction cache.

◆ MSC_EnableCache()

void MSC_EnableCache ( bool enable )

inline

Enable or disable instruction cache functionality.

Parameters

[in] enable Enable instruction cache. Default is on.

◆ MSC_EnableCacheIRQs()

void MSC_EnableCacheIRQs ( bool enable )

inline

Enable or disable instruction cache functionality in IRQs.

Parameters

[in] enable Enable instruction cache. Default is on.

◆ MSC_EnableAutoCacheFlush()

void MSC_EnableAutoCacheFlush ( bool enable )

inline

Enable or disable instruction cache flushing when writing to flash.

Parameters

[in] enable Enable automatic cache flushing. Default is on.

◆ MSC_ExecConfigSet()

void MSC_ExecConfigSet ( MSC_ExecConfig_TypeDef * execConfig )

Set the MSC code execution configuration.

Parameters

[in] execConfig The code execution configuration.

◆ MSC_WriteWordFast()

MSC_RAMFUNC_DEFINITION_END MSC_RAMFUNC_DEFINITION_BEGIN MSC_Status_TypeDef MSC_WriteWordFast	(	uint32_t *	`address,`
		void const *	`data,`
		uint32_t	`numBytes`
	)

Writes data to flash memory.

This function is faster than MSC_WriteWord(), but it disables interrupts. Write data must be aligned to words and contain a number of bytes that is divisible by four.

Warning: This function is only available for certain devices.

Note: It is recommended to erase the flash page before performing a write. It is required to run this function from RAM on parts that include a flash write buffer.

For IAR Embedded Workbench, Simplicity Studio and GCC, this is done automatically by using attributes in the function proctype. For Keil uVision IDE, define a section called "ram_code" and place this manually in the project's scatter file.

Parameters

[in]	`address`	A pointer to the flash word to write to. Must be aligned to words.
[in]	`data`	Data to write to flash.
[in]	`numBytes`	A number of bytes to write from the Flash. NB: Must be divisible by four.

Returns

Returns the status of the write operation.

*   flashReturnOk - The operation completed successfully.
*   flashReturnInvalidAddr - The operation tried to erase a non-flash area.
*   flashReturnLocked - The operation tried to erase a locked area of the flash.
*   flashReturnTimeOut - The operation timed out waiting for flash operation
*       to complete. Or the MSC timed out waiting for the software to write
*       the next word into the DWORD register.
*

◆ MSC_MassErase()

SL_RAMFUNC_DEFINITION_BEGIN MSC_Status_TypeDef MSC_MassErase ( void )

Erase the entire Flash in one operation.

Note: This command will erase the entire contents of the device. Use with care, both a debug session and all contents of the flash will be lost. The lock bit, MLW will prevent this operation from executing and might prevent a successful mass erase.

Returns: Returns the status of the operation.

◆ MSC_ErasePage()

MSC_RAMFUNC_DEFINITION_BEGIN MSC_Status_TypeDef MSC_ErasePage ( uint32_t * startAddress )

Erases a page in flash memory.

Note: For the Gecko family, it is required to run this function from RAM.

For IAR Embedded Workbench, Simplicity Studio and GCC, this is achieved automatically by using attributes in the function proctype. For Keil uVision IDE, define a section called "ram_code" and place this manually in the project's scatter file.

Parameters

[in] startAddress A pointer to the flash page to erase. Must be aligned to the beginning of the page boundary.

Returns

Returns the status of erase operation, MSC_Status_TypeDef

*   mscReturnOk - The operation completed successfully.
*   mscReturnInvalidAddr - The operation tried to erase a non-flash area.
*   mscReturnLocked - The operation tried to erase a locked area of the flash.
*   mscReturnTimeOut - The operation timed out waiting for the flash operation
*       to complete.
*

◆ MSC_WriteWord()

MSC_RAMFUNC_DEFINITION_END MSC_RAMFUNC_DEFINITION_BEGIN MSC_Status_TypeDef MSC_WriteWord	(	uint32_t *	`address,`
		void const *	`data,`
		uint32_t	`numBytes`
	)

Writes data to flash memory.

This function is interrupt-safe, but slower than MSC_WriteWordFast(), which writes to flash with interrupts disabled. Write data must be aligned to words and contain a number of bytes that is divisible by four.

Note: It is recommended to erase the flash page before performing a write.

For the Gecko family, it is required to run this function from RAM.

For IAR Embedded Workbench, Simplicity Studio and GCC, this is done automatically by using attributes in the function proctype. For Keil uVision IDE, define a section called "ram_code" and place it manually in the project's scatter file.

This function requires a system core clock at 1 MHz or higher.

Parameters

[in]	`address`	A pointer to the flash word to write to. Must be aligned to words.
[in]	`data`	Data to write to flash.
[in]	`numBytes`	A number of bytes to write from flash. NB: Must be divisible by four.

Returns

Returns the status of the write operation.

*   flashReturnOk - The operation completed successfully.
*   flashReturnInvalidAddr - The operation tried to erase a non-flash area.
*   flashReturnLocked - The operation tried to erase a locked area of the Flash.
*   flashReturnTimeOut - The operation timed out waiting for the flash operation
*       to complete, or the MSC module timed out waiting for the software to write
*       the next word into the DWORD register.
*

◆ MSC_WriteWordDma()

MSC_RAMFUNC_DEFINITION_END MSC_Status_TypeDef MSC_WriteWordDma	(	int	`ch,`
		uint32_t *	`address,`
		const void *	`data,`
		uint32_t	`numBytes`
	)

Writes data from RAM to flash memory using the DMA.

This function uses the LDMA to write data to the internal flash memory. This is the fastest way to write data to the flash and should be used when the application wants to achieve write speeds like they are reported in the datasheet. Note that this function only supports writing data from RAM to flash, it does not support writing data from flash to flash.

Note: This function requires that the LDMA clock is enabled.

Parameters

[in]	`ch`	DMA channel to use
[in]	`address`	A pointer to the flash word to write to. Must be aligned to words.
[in]	`data`	Data to write to flash. Note that this argument must be an address in RAM. This function does not support copying data from flash to flash on series-1 devices.
[in]	`numBytes`	A number of bytes to write from flash. NB: Must be divisible by four.

Returns

Returns the status of the write operation.

*   flashReturnOk - The operation completed successfully.
*   flashReturnInvalidAddr - The operation tried to erase a non-flash area.
*

◆ MSC_Init()

void MSC_Init ( void )

Enables the flash controller for writing.

Note: This function must be called before flash operations when AUXHFRCO clock has been changed from a default band.

◆ MSC_Deinit()

void MSC_Deinit ( void )

Disables the flash controller for writing.

Macro Definition Documentation

◆ MSC_PROGRAM_TIMEOUT

#define MSC_PROGRAM_TIMEOUT 10000000UL

Timeout used while waiting for Flash to become ready after a write.

This number indicates the number of iterations to perform before issuing a timeout.

Note: Timeout is set very large (in the order of 100x longer than necessary). This is to avoid any corner case.

◆ MSC_EXECCONFIG_DEFAULT

#define MSC_EXECCONFIG_DEFAULT

Value:

  {                            \
    false,                     \
    true,                      \
    false,                     \
    false,                     \
    false,                     \
    false,                     \
  }

Default MSC ExecConfig initialization.

Enumeration Type Documentation

◆ MSC_Status_TypeDef

enum MSC_Status_TypeDef

Return codes for writing/erasing Flash.

Enumerator
mscReturnOk	Flash write/erase successful.
mscReturnInvalidAddr	Invalid address. Write to an address that is not Flash.
mscReturnLocked	Flash address is locked.
mscReturnTimeOut	Timeout while writing to Flash.
mscReturnUnaligned	Unaligned access to Flash.

MSC - Memory System Controller

Description

Data Structures

Functions

Macros

Enumerations

Function Documentation

◆ MSC_LockGetLocked()

◆ MSC_LockSetLocked()

◆ MSC_LockSetUnlocked()

◆ MSC_ReadCTRLGet()

◆ MSC_ReadCTRLSet()

◆ MSC_IntClear()

◆ MSC_IntDisable()

◆ MSC_IntEnable()

◆ MSC_IntGet()

◆ MSC_IntGetEnabled()

◆ MSC_IntSet()

◆ MSC_StartCacheMeasurement()

◆ MSC_GetCacheMeasurement()

◆ MSC_FlushCache()

◆ MSC_EnableCache()

◆ MSC_EnableCacheIRQs()

◆ MSC_EnableAutoCacheFlush()

◆ MSC_ExecConfigSet()

◆ MSC_WriteWordFast()

◆ MSC_MassErase()

◆ MSC_ErasePage()

◆ MSC_WriteWord()

◆ MSC_WriteWordDma()

◆ MSC_Init()

◆ MSC_Deinit()

Macro Definition Documentation

◆ MSC_PROGRAM_TIMEOUT

◆ MSC_EXECCONFIG_DEFAULT

Enumeration Type Documentation

◆ MSC_Status_TypeDef