MSCEMLIB

Detailed 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 module. 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.

Support for Flash write and erase runs from RAM by default. This code may be allocated to Flash by defining EM_MSC_RUN_FROM_FLASH .

Note
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_WriteWordFast() , MSC_ErasePage() , and MSC_MassErase() . Fast write is not supported for EFM32G and 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));

Data Structures

struct MSC_ExecConfig_TypeDef

Macros

#define EM_MSC_RUN_FROM_FLASH
By compiling with define EM_MSC_RUN_FROM_FLASH, functions performing erase or write operations will remain in and execute from Flash. This is useful for targets that don't want to allocate RAM space to hold the flash functions. Without this define, code for Flash operations will be copied into RAM at startup.
#define MSC_EXECCONFIG_DEFAULT
#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.
#define MSC_RAMFUNC_DECLARATOR
Expands to SL_RAMFUNC_DECLARATOR if EM_MSC_RUN_FROM_FLASH is undefined and to nothing if EM_MSC_RUN_FROM_FLASH is defined.
#define MSC_RAMFUNC_DEFINITION_BEGIN
Expands to SL_RAMFUNC_DEFINITION_BEGIN if EM_MSC_RUN_FROM_FLASH is undefined and to nothing if EM_MSC_RUN_FROM_FLASH is defined.
#define MSC_RAMFUNC_DEFINITION_END
Expands to SL_RAMFUNC_DEFINITION_END if EM_MSC_RUN_FROM_FLASH is undefined and to nothing if EM_MSC_RUN_FROM_FLASH is defined.

Enumerations

enum MSC_Status_TypeDef {
mscReturnOk = 0,
mscReturnInvalidAddr = -1,
mscReturnLocked = -2,
mscReturnTimeOut = -3,
mscReturnUnaligned = -4
}

Functions

void MSC_Deinit (void)
Disables the flash controller for writing.
__STATIC_INLINE void MSC_EnableAutoCacheFlush (bool enable)
Enable or disable instruction cache flushing when writing to flash.
__STATIC_INLINE void MSC_EnableCache (bool enable)
Enable or disable instruction cache functionality.
__STATIC_INLINE void MSC_EnableCacheIRQs (bool enable)
Enable or disable instruction cache functionality in IRQs.
MSC_RAMFUNC_DECLARATOR MSC_Status_TypeDef MSC_ErasePage (uint32_t *startAddress)
Erases a page in flash memory.
void MSC_ExecConfigSet ( MSC_ExecConfig_TypeDef *execConfig)
Set the MSC code execution configuration.
__STATIC_INLINE void MSC_FlushCache (void)
Flush contents of instruction cache.
__STATIC_INLINE int32_t MSC_GetCacheMeasurement (void)
Stops measuring hit rate.
void MSC_Init (void)
Enables the flash controller for writing.
__STATIC_INLINE void MSC_IntClear (uint32_t flags)
Clear one or more pending MSC interrupts.
__STATIC_INLINE void MSC_IntDisable (uint32_t flags)
Disable one or more MSC interrupts.
__STATIC_INLINE void MSC_IntEnable (uint32_t flags)
Enable one or more MSC interrupts.
__STATIC_INLINE uint32_t MSC_IntGet (void)
Get pending MSC interrupt flags.
__STATIC_INLINE uint32_t MSC_IntGetEnabled (void)
Get enabled and pending MSC interrupt flags. Useful for handling more interrupt sources in the same interrupt handler.
__STATIC_INLINE void MSC_IntSet (uint32_t flags)
Set one or more pending MSC interrupts from SW.
MSC_RAMFUNC_DECLARATOR MSC_Status_TypeDef MSC_MassErase (void)
Erase the entire Flash in one operation.
__STATIC_INLINE void MSC_StartCacheMeasurement (void)
Starts measuring cache hit ratio.
MSC_RAMFUNC_DECLARATOR 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.
MSC_RAMFUNC_DECLARATOR 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.

Macro Definition Documentation

#define EM_MSC_RUN_FROM_FLASH

By compiling with define EM_MSC_RUN_FROM_FLASH, functions performing erase or write operations will remain in and execute from Flash. This is useful for targets that don't want to allocate RAM space to hold the flash functions. Without this define, code for Flash operations will be copied into RAM at startup.

Note
This define is not present by default. The MSC controller API will run from RAM by default.

Definition at line 125 of file em_msc.h .

#define MSC_EXECCONFIG_DEFAULT
Value:
{ \
false, \
true, \
false, \
false, \
false, \
false, \
}

Default MSC ExecConfig initialization.

Definition at line 162 of file em_msc.h .

#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.

Definition at line 110 of file em_msc.h .

Referenced by MSC_ErasePage() .

Enumeration Type Documentation

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.

Definition at line 133 of file em_msc.h .

Function Documentation

__STATIC_INLINE void MSC_EnableAutoCacheFlush ( bool enable )

Enable or disable instruction cache flushing when writing to flash.

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

Definition at line 436 of file em_msc.h .

References _MSC_READCTRL_AIDIS_SHIFT , BUS_RegBitWrite() , and MSC .

__STATIC_INLINE void MSC_EnableCache ( bool enable )

Enable or disable instruction cache functionality.

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

Definition at line 412 of file em_msc.h .

References _MSC_READCTRL_IFCDIS_SHIFT , BUS_RegBitWrite() , and MSC .

__STATIC_INLINE void MSC_EnableCacheIRQs ( bool enable )

Enable or disable instruction cache functionality in IRQs.

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

Definition at line 424 of file em_msc.h .

References _MSC_READCTRL_ICCDIS_SHIFT , BUS_RegBitWrite() , and MSC .

MSC_RAMFUNC_DEFINITION_BEGIN MSC_Status_TypeDef MSC_ErasePage ( uint32_t * startAddress )

Erases a page in flash memory.

Note
It is recommended to run this code from RAM. On the Gecko family, it is required to run this function from RAM.

For IAR IDE, Rowley IDE, SimplicityStudio IDE, Atollic IDE, and ARM GCC IDE, 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.
*

Definition at line 975 of file em_msc.c .

References EMU , FLASH_PAGE_SIZE , MSC , MSC_PROGRAM_TIMEOUT , MSC_STATUS_BUSY , MSC_STATUS_INVADDR , MSC_STATUS_LOCKED , MSC_WRITECMD_ERASEPAGE , MSC_WRITECMD_LADDRIM , MSC_WRITECTRL_WREN , mscReturnInvalidAddr , mscReturnLocked , mscReturnOk , and mscReturnTimeOut .

Referenced by nvm3_halPageErase() , and NVMHAL_PageErase() .

void MSC_ExecConfigSet ( MSC_ExecConfig_TypeDef * execConfig )

Set the MSC code execution configuration.

Parameters
[in] execConfig The code execution configuration.

Definition at line 291 of file em_msc.c .

References _MSC_READCTRL_MODE_MASK , MSC_ExecConfig_TypeDef::aiDis , MSC_ExecConfig_TypeDef::iccDis , MSC_ExecConfig_TypeDef::ifcDis , MSC , MSC_READCTRL_AIDIS , MSC_READCTRL_ICCDIS , MSC_READCTRL_IFCDIS , MSC_READCTRL_MODE_WS0 , MSC_READCTRL_MODE_WS1 , MSC_READCTRL_PREFETCH , MSC_READCTRL_SCBTP , MSC_READCTRL_USEHPROT , MSC_ExecConfig_TypeDef::prefetchEn , MSC_ExecConfig_TypeDef::scbtEn , and MSC_ExecConfig_TypeDef::useHprot .

__STATIC_INLINE int32_t MSC_GetCacheMeasurement ( void )

Stops measuring 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.

Definition at line 366 of file em_msc.h .

References MSC , MSC_CACHECMD_STOPPC , MSC_IF_CHOF , and MSC_IF_CMOF .

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.

Definition at line 225 of file em_msc.c .

References CMU_ClockFreqGet() , cmuClock_AUX , EMU , MSC , MSC_UNLOCK_CODE , and MSC_WRITECTRL_WREN .

Referenced by nvm3_halOpen() , and NVMHAL_Init() .

__STATIC_INLINE void MSC_IntClear ( uint32_t flags )

Clear one or more pending MSC interrupts.

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

Definition at line 213 of file em_msc.h .

References MSC .

__STATIC_INLINE void MSC_IntDisable ( uint32_t flags )

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).

Definition at line 226 of file em_msc.h .

References MSC .

__STATIC_INLINE void MSC_IntEnable ( uint32_t flags )

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).

Definition at line 244 of file em_msc.h .

References MSC .

__STATIC_INLINE uint32_t MSC_IntGet ( void )

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).

Definition at line 260 of file em_msc.h .

References MSC .

__STATIC_INLINE uint32_t MSC_IntGetEnabled ( void )

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

Definition at line 279 of file em_msc.h .

References MSC .

__STATIC_INLINE void MSC_IntSet ( uint32_t flags )

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).

Definition at line 295 of file em_msc.h .

References MSC .

MSC_RAMFUNC_DEFINITION_END MSC_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.

Definition at line 1127 of file em_msc.c .

References MSC , MSC_MASSLOCK_LOCKKEY_LOCK , MSC_MASSLOCK_LOCKKEY_UNLOCK , MSC_STATUS_BUSY , MSC_WRITECMD_ERASEMAIN0 , MSC_WRITECTRL_WREN , and mscReturnOk .

__STATIC_INLINE void MSC_StartCacheMeasurement ( void )

Starts measuring cache hit ratio.

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

Definition at line 308 of file em_msc.h .

References MSC , MSC_CACHECMD_STARTPC , MSC_IF_CHOF , and MSC_IF_CMOF .

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.

It is recommended to run this code from RAM. On the Gecko family, it is required to run this function from RAM.

For IAR IDE, Rowley IDE, SimplicityStudio IDE, Atollic IDE, and ARM GCC IDE, 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.
*

Definition at line 1061 of file em_msc.c .

Referenced by nvm3_halWriteWords() , and NVMHAL_Write() .

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.

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 IDE, Rowley IDE, SimplicityStudio IDE, Atollic IDE, and ARM GCC IDE, 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.
*

Definition at line 1104 of file em_msc.c .