3.18.1 NVMCTRL
- Non-Volatile Memory Controller
3.18.1.1 Introduction
The NVM module provides run-time read and write access to the Program Flash Memory (PFM), Data Flash Memory (DFM) and Configuration bits. PFM includes the program memory and user ID space while DFM is also referred to as EEPROM which is accessed one byte at a time and the erase before write is automatic.
3.18.1.2 Supported Device Families
PIC12F184x | PIC16F184x | PIC16F178x | PIC16F194x |
PIC18F-K20 | PIC18F-K22 | PIC18F-K40 | PIC18F-K42 |
PIC18F-K50 | PIC18F-K80 | PIC18F-K83 | PIC18F-K90 |
3.18.1.3 Required header files:
#include "mcc_generated_files/nvm/nvm.h"
3.18.1.4 How to use the Memory Driver
The Memory driver can be used to access different types of memory. Click the links below to view examples on how to access the Flash and EEPROM memory.
- Accessing the Flash Memory
- Accessing the EEPROM Memory
- Accessing the Device ID
- Accessing the Configuration settings
3.18.1.5 Module Documentation
3.18.1.5.1 Non-Volatile Memory
This file contains API prototypes and other data types for the Non-Volatile Memory (NVM) driver.
Module description
This file contains API prototypes and other data types for the Non-Volatile Memory (NVM) driver.
Typedefs
typedef uint8_t flash_data_t
Data type for the Flash data.
typedef uint24_t flash_address_t
Data type for the Flash address.
typedef uint8_t eeprom_data_t
Data type for the EEPROM data.
typedef uint24_t eeprom_address_t
Data type for the EEPROM address.
typedef uint16_t device_id_data_t
Data type for the Device ID data.
typedef uint24_t device_id_address_t
Data type for the Device ID address.
typedef uint8_t configuration_data_t
Data type for the Configurations Settings data.
typedef uint24_t configuration_address_t
Data type for the Configurations Settings address.
Definitions
#define PROGMEM_PAGE_SIZE (128U)
#define PROGMEM_SIZE (0x020000U)
#define EEPROM_START_ADDRESS (0x310000U)
#define EEPROM_SIZE (1024U)
#define UNLOCK_KEY (0xAA55U)
Enumerations
enum nvm_status_t { NVM_OK, NVM_ERROR }
Contains the return codes for the NVM APIs.
Functions
void NVM_Initialize (void)
Initializes the NVM driver.
bool NVM_IsBusy (void)
Checks if the NVM is busy with the read/write/erase commands.
nvm_status_t NVM_StatusGet (void)
Returns the status of the last NVM operation.
void NVM_StatusClear (void)
Clears the NVM error status.
void NVM_UnlockKeySet (uint16_t unlockKey)
Sets the unlock keys required to perform any erase or write operations on Flash and EEPROM.
void NVM_UnlockKeyClear (void)
Clears the previously configured unlock keys.
flash_data_t FLASH_Read (flash_address_t address)
Reads a byte from the given address of Flash.
nvm_status_t FLASH_RowWrite (flash_address_t address, flash_data_t *dataBuffer)
Writes one entire Flash row (page) from the given starting address of the row (the first byte location). The size of the input buffer must be one Flash row and the address must be aligned with the row boundary. Use FLASH_PageAddressGet() to obtain the starting address of the row.
nvm_status_t FLASH_PageErase (flash_address_t address)
Erases one Flash page containing the given address.
flash_address_t FLASH_PageAddressGet (flash_address_t address)
Returns the starting address of the page (the first byte location) containing the given Flash address.
uint16_t FLASH_PageOffsetGet (flash_address_t address)
Returns the offset from the starting address of the page (the first byte location).
eeprom_data_t EEPROM_Read (eeprom_address_t address)
Reads one byte from the given EEPROM address.
void EEPROM_Write (eeprom_address_t address, eeprom_data_t data)
Writes one byte to the given EEPROM address. The NVM busy status must be checked using the NVM_IsBusy() API to know if the write operation is completed.
device_id_data_t DeviceID_Read (device_id_address_t address)
Reads the Device ID.
configuration_data_t CONFIGURATION_Read (configuration_address_t address)
Reads one Configuration byte.
void CONFIGURATION_Write (configuration_address_t address, configuration_data_t data)
Writes one Configuration byte. The NVM busy status must be checked using the NVM_IsBusy() API to know if the write operation is completed.
void NVM_InterruptEnable (void)
Enables the NVM interrupt.
void NVM_InterruptDisable (void)
Disables the NVM interrupt.
void NVM_CallbackRegister (void(*CallbackHandler)(void))
Setter function for the NVM interrupt callback.
Definition Documentation
EEPROM_SIZE
#define EEPROM_SIZE (1024U)
Contains the size of EEPROM in bytes.
EEPROM_START_ADDRESS
#define EEPROM_START_ADDRESS (0x310000U)
Contains the starting address of EEPROM.
PROGMEM_PAGE_SIZE
#define PROGMEM_PAGE_SIZE (128U)
Contains the size of a Flash page in bytes.
PROGMEM_SIZE
#define PROGMEM_SIZE (0x020000U)
Contains the size of Flash in bytes.
UNLOCK_KEY
#define UNLOCK_KEY (0xAA55U)
Contains the unlock key required for the NVM operations.
Typedef Documentation
configuration_address_t
typedef uint24_t configuration_address_t
Data type for the Configurations Settings address.
configuration_data_t
typedef uint8_t configuration_data_t
Data type for the Configurations Settings data.
device_id_address_t
typedef uint24_t device_id_address_t
Data type for the Device ID address.
device_id_data_t
typedef uint16_t device_id_data_t
Data type for the Device ID data.
eeprom_address_t
typedef uint24_t eeprom_address_t
Data type for the EEPROM address.
eeprom_data_t
typedef uint8_t eeprom_data_t
Data type for the EEPROM data.
flash_address_t
typedef uint24_t flash_address_t
Data type for the Flash address.
flash_data_t
typedef uint8_t flash_data_t
Data type for the Flash data.
Function Documentation
CONFIGURATION_Read()
configuration_data_t CONFIGURATION_Read (configuration_address_t address)
Reads one Configuration byte.
|
Configuration byte data. |
CONFIGURATION_Write()
void CONFIGURATION_Write (configuration_address_t address, configuration_data_t data)
Writes one Configuration byte. The NVM busy status must be checked using the NVM_IsBusy() API to know if the write operation is completed.
Set the unlock key using the NVM_UnlockKeySet() API, if the key has been cleared before. AoU: Address Qualifiers must be configured to Require under Project Properties>XC8 Compiler>Optimizations. |
|
None. |
DeviceID_Read()
device_id_data_t DeviceID_Read (device_id_address_t address)
Reads the Device ID.
|
Device ID. |
EEPROM_Read()
eeprom_data_t EEPROM_Read (eeprom_address_t address)
Reads one byte from the given EEPROM address.
|
Byte read from the given EEPROM address. |
EEPROM_Write()
void EEPROM_Write (eeprom_address_t address, eeprom_data_t data)
Writes one byte to the given EEPROM address. The NVM busy status must be checked using the NVM_IsBusy() API to know if the write operation is completed.
Set the unlock key using the NVM_UnlockKeySet() API, if the key has been cleared before. AoU: Address Qualifiers must be configured to Require under Project Properties>XC8 Compiler>Optimizations. |
|
None. |
FLASH_PageAddressGet()
flash_address_t FLASH_PageAddressGet (flash_address_t address)
Returns the starting address of the page (the first byte location) containing the given Flash address.
|
Starting address of the page containing the given Flash address. |
FLASH_PageErase()
nvm_status_t FLASH_PageErase (flash_address_t address)
Erases one Flash page containing the given address.
Set the unlock key using the NVM_UnlockKeySet() API, if the key has been cleared before. AoU: Address Qualifiers must be configured to Require under Project Properties>XC8 Compiler>Optimizations. |
|
Status of the Flash page erase operation as described in nvm_status_t. |
FLASH_PageOffsetGet()
uint16_t FLASH_PageOffsetGet (flash_address_t address)
Returns the offset from the starting address of the page (the first byte location).
|
Offset of the given address from the starting address of the page. |
FLASH_Read()
flash_data_t FLASH_Read (flash_address_t address)
Reads a byte from the given address of Flash.
|
Byte read from the given Flash address. |
FLASH_RowWrite()
nvm_status_t FLASH_RowWrite (flash_address_t address, flash_data_t * dataBuffer)
Writes one entire Flash row (page) from the given starting address of the row (the first byte location). The size of the input buffer must be one Flash row and the address must be aligned with the row boundary. Use FLASH_PageAddressGet() to obtain the starting address of the row.
Erase Flash row before calling this function. Set the unlock key using the NVM_UnlockKeySet() API, if the key has been cleared before. AoU: Address Qualifiers must be configured to Require under Project Properties>XC8 Compiler>Optimizations. |
|
Status of the Flash row write operation as described in nvm_status_t. |
NVM_CallbackRegister()
void NVM_CallbackRegister (void(*)(void) CallbackHandler)
Setter function for the NVM interrupt callback.
|
None. |
NVM_Initialize()
void NVM_Initialize (void )
Initializes the NVM driver.
|
None. |
NVM_InterruptDisable()
void NVM_InterruptDisable (void )[inline]
Disables the NVM interrupt.
|
None. |
NVM_InterruptEnable()
void NVM_InterruptEnable (void )[inline]
Enables the NVM interrupt.
Enable the global interrupt. |
|
None. |
NVM_IsBusy()
bool NVM_IsBusy (void )
Checks if the NVM is busy with the read/write/erase commands.
|
|
NVM_StatusClear()
void NVM_StatusClear (void )
Clears the NVM error status.
|
None. |
NVM_StatusGet()
nvm_status_t NVM_StatusGet (void )
Returns the status of the last NVM operation.
|
|
NVM_UnlockKeyClear()
void NVM_UnlockKeyClear (void )
Clears the previously configured unlock keys.
|
None. |
NVM_UnlockKeySet()
void NVM_UnlockKeySet (uint16_t unlockKey)
Sets the unlock keys required to perform any erase or write operations on Flash and EEPROM.
|
None. |
Enumeration Type Documentation
nvm_status_t
enum nvm_status_t
Contains the return codes for the NVM APIs.
NVM_OK |
0 - The NVM operation succeeded. | |
NVM_ERROR |
1 - The NVM operation failed. |
3.18.1.5.2 Nvm_example
Flash Examples
This example shows how to overwrite an entire Flash page with the new data using the row write feature:
#include "mcc_generated_files/system/system.h" #define FLASH_ADDRESS (PROGMEM_SIZE - 5) //Flash address at which data is to be written void FLASH_Example_PageErase_RowWrite_Read(void) { flash_address_t flashStartPageAddress; uint16_t index; flash_data_t flashWriteData[PROGMEM_PAGE_SIZE]; nvm_status_t errorStatus = NVM_OK; bool readError = false; //Get the starting address of the page containing the given address flashStartPageAddress = FLASH_PageAddressGet(FLASH_ADDRESS); //Erase entire page NVM_UnlockKeySet(UNLOCK_KEY); errorStatus = FLASH_PageErase(flashStartPageAddress); NVM_UnlockKeyClear(); if (errorStatus == NVM_OK) { printf("FLASH_PageErase passed \r\n"); } else { printf("FLASH_PageErase failed \r\n"); NVM_StatusClear(); } //Prepare row data for (index = 0; index < PROGMEM_PAGE_SIZE; index++) { flashWriteData[index] = (flash_data_t) index; } //Write data to Flash row NVM_UnlockKeySet(UNLOCK_KEY); errorStatus = FLASH_RowWrite(flashStartPageAddress, flashWriteData); NVM_UnlockKeyClear(); if (errorStatus == NVM_OK) { printf("FLASH_RowWrite passed \r\n"); } else { printf("FLASH_RowWrite failed \r\n"); NVM_StatusClear(); } //Read and verify row data for (index = 0; index < PROGMEM_PAGE_SIZE; index++) { if (FLASH_Read(flashStartPageAddress + index) != flashWriteData[index]) { readError = true; break; } } if (readError == false) { printf("FLASH_Read passed \r\n"); } else { printf("FLASH_Read failed \r\n"); } }
This example shows how to update specific locations in the given Flash page without disturbing other locations:
#include "mcc_generated_files/system/system.h" #define FLASH_ADDRESS (PROGMEM_SIZE - 5) //Flash address at which data is to be written void FLASH_Example_UpdateSelectiveLocations(void) { flash_address_t flashStartPageAddress; uint16_t flashAddressOffset; nvm_status_t errorStatus = NVM_OK; bool readError = false; flash_data_t flashWriteData[PROGMEM_PAGE_SIZE]; //Get the starting address of the page containing the given address flashStartPageAddress = FLASH_PageAddressGet(FLASH_ADDRESS); for (flashAddressOffset = 0; flashAddressOffset < PROGMEM_PAGE_SIZE; flashAddressOffset++) { flashWriteData[flashAddressOffset] = FLASH_Read(flashStartPageAddress + flashAddressOffset); } //Get offset from starting address of the page flashAddressOffset = FLASH_PageOffsetGet(FLASH_ADDRESS); //Update 4 bytes flashWriteData[flashAddressOffset] = 0x0A; flashWriteData[flashAddressOffset + 1] = 0x1A; flashWriteData[flashAddressOffset + 2] = 0x2A; flashWriteData[flashAddressOffset + 3] = 0x3A; //Erase entire Flash page NVM_UnlockKeySet(UNLOCK_KEY); errorStatus = FLASH_PageErase(flashStartPageAddress); NVM_UnlockKeyClear(); if (errorStatus == NVM_OK) { printf("FLASH_PageErase passed \r\n"); } else { printf("FLASH_PageErase failed \r\n"); NVM_StatusClear(); } //Write data to Flash row NVM_UnlockKeySet(UNLOCK_KEY); errorStatus = FLASH_RowWrite(flashStartPageAddress, flashWriteData); NVM_UnlockKeyClear(); if (errorStatus == NVM_OK) { printf("FLASH_RowWrite passed \r\n"); } else { printf("FLASH_RowWrite failed \r\n"); NVM_StatusClear(); } //Read and verify row data for (flashAddressOffset = 0; flashAddressOffset < PROGMEM_PAGE_SIZE; flashAddressOffset++) { if (FLASH_Read(flashStartPageAddress + flashAddressOffset) != flashWriteData[flashAddressOffset]) { readError = true; break; } } if (readError == false) { printf("FLASH_Read passed \r\n"); } else { printf("FLASH_Read failed \r\n"); } }
EEPROM Examples
This example shows how to perform the write and read operations on EEPROM:
#include "mcc_generated_files/system/system.h" #define EEPROM_ADDRESS (EEPROM_START_ADDRESS) //EEPROM address at which data is to be written void EEPROM_Write_Read(void) { eeprom_data_t eepromWriteData[8]; uint8_t count; bool readError = false; //Prepare data for (count = 0; count < 8; count++) { eepromWriteData[count] = 0xA1 + count; } for (count = 0; count < 8; count++) { //Write EEPROM byte NVM_UnlockKeySet(UNLOCK_KEY); EEPROM_Write(EEPROM_ADDRESS + count, eepromWriteData[count]); NVM_UnlockKeyClear(); while (NVM_IsBusy()); if (NVM_StatusGet() == NVM_OK) { printf("EEPROM_Write passed \r\n"); } else { printf("EEPROM_Write failed \r\n"); NVM_StatusClear(); } } //Read and verify for (count = 0; count < 8; count++) { if (EEPROM_Read(EEPROM_ADDRESS + count) != eepromWriteData[count]) { readError = true; break; } } if (readError == false) { printf("EEPROM_Read passed \r\n"); } else { printf("EEPROM_Read failed \r\n"); } }
Device ID Examples
This example shows how to read the Device ID:
#include "mcc_generated_files/system/system.h" #define DEVICE_ID_ADDRESS (0x3FFFFEU) //(Compare with the device data sheet to see if the address is correct) void NVM_Example_DeviceID_Read(void) { printf("Device ID : 0x%X \r\n", DeviceID_Read(DEVICE_ID_ADDRESS)); }
Configuration Settings Examples
This example shows how to update the specific Configuration setting without disturbing the other settings:
#include "mcc_generated_files/system/system.h" #define CONFIG_TO_BE_UPDATED_ADDRESS (0x300000U) //CONFIG1 address (Compare with the device data sheet to see if the address is correct) #define _CONFIG1_FEXTOSC_MASK (0b111) void NVM_Example_Configuration_UpdateSpecifcSetting(void) { configuration_address_t configurationToBeUpdatedAddress = CONFIG_TO_BE_UPDATED_ADDRESS; configuration_data_t configurationValueToBeUpdated; //Read configurationValueToBeUpdated = CONFIGURATION_Read(configurationToBeUpdatedAddress); //Modify configurationValueToBeUpdated &= (~((configuration_data_t)_CONFIG1_FEXTOSC_MASK)); //Clear External Oscillator Mode Selection bits //Write NVM_UnlockKeySet(UNLOCK_KEY); CONFIGURATION_Write(configurationToBeUpdatedAddress, configurationValueToBeUpdated); NVM_UnlockKeyClear(); while (NVM_IsBusy()); if (NVM_StatusGet() == NVM_OK) { printf("CONFIGURATION_Write passed \r\n"); } else { printf("CONFIGURATION_Write failed \r\n"); NVM_StatusClear(); } //Read again to verify if(configurationValueToBeUpdated == CONFIGURATION_Read(configurationToBeUpdatedAddress)) { printf("CONFIGURATION_Read passed \r\n"); } else { printf("CONFIGURATION_Read failed \r\n"); } }
3.18.1.6 File Documentation
3.18.1.6.1 source/nvm.c File Reference
This file contains the API implementations for the Non-Volatile Memory (NVM) driver.
#include "../nvm.h"
Functions
void NVM_Initialize (void)
Initializes the NVM driver.
bool NVM_IsBusy (void)
Checks if the NVM is busy with the read/write/erase commands.
nvm_status_t NVM_StatusGet (void)
Returns the status of the last NVM operation.
void NVM_StatusClear (void)
Clears the NVM error status.
void NVM_UnlockKeySet (uint16_t unlockKey)
Sets the unlock keys required to perform any erase or write operations on Flash and EEPROM.
void NVM_UnlockKeyClear (void)
Clears the previously configured unlock keys.
flash_data_t FLASH_Read (flash_address_t address)
Reads a byte from the given address of Flash.
nvm_status_t FLASH_RowWrite (flash_address_t address, flash_data_t *dataBuffer)
Writes one entire Flash row (page) from the given starting address of the row (the first byte location). The size of the input buffer must be one Flash row and the address must be aligned with the row boundary. Use FLASH_PageAddressGet() to obtain the starting address of the row.
nvm_status_t FLASH_PageErase (flash_address_t address)
Erases one Flash page containing the given address.
flash_address_t FLASH_PageAddressGet (flash_address_t address)
Returns the starting address of the page (the first byte location) containing the given Flash address.
uint16_t FLASH_PageOffsetGet (flash_address_t address)
Returns the offset from the starting address of the page (the first byte location).
eeprom_data_t EEPROM_Read (eeprom_address_t address)
Reads one byte from the given EEPROM address.
void EEPROM_Write (eeprom_address_t address, eeprom_data_t data)
Writes one byte to the given EEPROM address. The NVM busy status must be checked using the NVM_IsBusy() API to know if the write operation is completed.
device_id_data_t DeviceID_Read (device_id_address_t address)
Reads the Device ID.
configuration_data_t CONFIGURATION_Read (configuration_address_t address)
Reads one Configuration byte.
void CONFIGURATION_Write (configuration_address_t address, configuration_data_t data)
Writes one Configuration byte. The NVM busy status must be checked using the NVM_IsBusy() API to know if the write operation is completed.
void NVM_InterruptEnable (void)
Enables the NVM interrupt.
void NVM_InterruptDisable (void)
Disables the NVM interrupt.
void __interrupt (irq(NVM), base(8), low_priority)
void NVM_CallbackRegister (void(*CallbackHandler)(void))
Setter function for the NVM interrupt callback.
Variables
__near static volatile uint8_t unlockKeyLow
__near static volatile uint8_t unlockKeyHigh
static void(* NVM_Callback )(void) = NULL
Detailed Description
This file contains the API implementations for the Non-Volatile Memory (NVM) driver.
Function Documentation
__interrupt()
void __interrupt (irq(NVM) , base(8) , low_priority )
Variable Documentation
NVM_Callback
void(* NVM_Callback) (void) = NULL[static]
unlockKeyHigh
__near static volatile uint8_t unlockKeyHigh[static]
unlockKeyLow
__near static volatile uint8_t unlockKeyLow[static]
3.18.1.6.2 source/nvm.h File Reference
#include <xc.h> #include <stdbool.h>
Functions
void NVM_Initialize (void)
Initializes the NVM driver.
bool NVM_IsBusy (void)
Checks if the NVM is busy with the read/write/erase commands.
nvm_status_t NVM_StatusGet (void)
Returns the status of the last NVM operation.
void NVM_StatusClear (void)
Clears the NVM error status.
void NVM_UnlockKeySet (uint16_t unlockKey)
Sets the unlock keys required to perform any erase or write operations on Flash and EEPROM.
void NVM_UnlockKeyClear (void)
Clears the previously configured unlock keys.
flash_data_t FLASH_Read (flash_address_t address)
Reads a byte from the given address of Flash.
nvm_status_t FLASH_RowWrite (flash_address_t address, flash_data_t *dataBuffer)
Writes one entire Flash row (page) from the given starting address of the row (the first byte location). The size of the input buffer must be one Flash row and the address must be aligned with the row boundary. Use FLASH_PageAddressGet() to obtain the starting address of the row.
nvm_status_t FLASH_PageErase (flash_address_t address)
Erases one Flash page containing the given address.
flash_address_t FLASH_PageAddressGet (flash_address_t address)
Returns the starting address of the page (the first byte location) containing the given Flash address.
uint16_t FLASH_PageOffsetGet (flash_address_t address)
Returns the offset from the starting address of the page (the first byte location).
eeprom_data_t EEPROM_Read (eeprom_address_t address)
Reads one byte from the given EEPROM address.
void EEPROM_Write (eeprom_address_t address, eeprom_data_t data)
Writes one byte to the given EEPROM address. The NVM busy status must be checked using the NVM_IsBusy() API to know if the write operation is completed.
device_id_data_t DeviceID_Read (device_id_address_t address)
Reads the Device ID.
configuration_data_t CONFIGURATION_Read (configuration_address_t address)
Reads one Configuration byte.
void CONFIGURATION_Write (configuration_address_t address, configuration_data_t data)
Writes one Configuration byte. The NVM busy status must be checked using the NVM_IsBusy() API to know if the write operation is completed.
void NVM_InterruptEnable (void)
Enables the NVM interrupt.
void NVM_InterruptDisable (void)
Disables the NVM interrupt.
void NVM_CallbackRegister (void(*CallbackHandler)(void))
Setter function for the NVM interrupt callback.
Macros
#define PROGMEM_PAGE_SIZE (128U)
#define PROGMEM_SIZE (0x020000U)
#define EEPROM_START_ADDRESS (0x310000U)
#define EEPROM_SIZE (1024U)
#define UNLOCK_KEY (0xAA55U)
Typedefs
typedef uint8_t flash_data_t
Data type for the Flash data.
typedef uint24_t flash_address_t
Data type for the Flash address.
typedef uint8_t eeprom_data_t
Data type for the EEPROM data.
typedef uint24_t eeprom_address_t
Data type for the EEPROM address.
typedef uint16_t device_id_data_t
Data type for the Device ID data.
typedef uint24_t device_id_address_t
Data type for the Device ID address.
typedef uint8_t configuration_data_t
Data type for the Configurations Settings data.
typedef uint24_t configuration_address_t
Data type for the Configurations Settings address.
Enumerations
enum nvm_status_t { NVM_OK, NVM_ERROR }
Contains the return codes for the NVM APIs.
Macro Definition Documentation
FLASH_ErasePageAddressGet
#define FLASH_ErasePageAddressGet FLASH_PageAddressGet
FLASH_ErasePageOffsetGet
#define FLASH_ErasePageOffsetGet FLASH_PageOffsetGet