3.32.16 Non-Volatile Memory Controller (NVMCTRL)

Using The Library

NVMCTRL Peripheral library provides non-Blocking API's and they can be used to perform below functionalities on the NVMCTRL peripheral.

• Initialize the NVMCTRL

• Register a callback

• Perform NVM write and erase operations

• Manage region locks

• Manage SmartEEPROM

• Check error and status of NVM

The Flash memory main address space on this device is arranged as two memory banks. It is possible to execute code from one memory bank while a write or erase operation is progressing on the other memory bank. The entire flash memory is divided into 32 regions.

Each region has a corresponding lock bit which can be programmed (with Lock Region command) to temporarily prevent write and erase operations. Temporarily here means until the region is unlocked with an unlock command. These lock bits can be erased (with an Unlock Region command)) to temporarily unlock a region. When the device is reset, region lock values are loaded with the default value stored in the NVM User Page.

The main address space is divided into blocks . Each of the block contains several flash pages. Commands used for the main address space and NVM User Page are different.

There are multiple commands to perform erase and write operations.

• EB: Erase Block

• EP: Erase Page

• WP: Write Page

• WQW: Write Quad Word

SmartEEPROM is the feature which perform EEPROM emulation on the device flash. There are fuse bits in the NVM User Page to configure SmartEEPROM total size and page size. Refer the datasheet and code examples for more details on the SmartEEPROM.

Here is an example code to erase a block and program a page of memory using polling method

// Define a constant array in Flash.
// It must be aligned to block boundary and size has to be in multiple of rows
const uint8_t nvm_user_start_address[NVMCTRL_FLASH_BLOCKSIZE] __attribute__((aligned(NVMCTRL_FLASH_BLOCKSIZE),keep,externally_visible,space(prog)))= {0};

void populate_buffer(uint8_t* data)
{
    int i = 0;

    for (i = 0; i < (NVMCTRL_FLASH_PAGESIZE); i++)
    {
        *(data + i) = i;
    }
}

int main (void)
{
    uint8_t pageBuffer[NVMCTRL_FLASH_PAGESIZE] = {0};

    /*Populate pageBuffer to programmed*/
    populate_buffer(pageBuffer);

    while(NVMCTRL_IsBusy());

    /* Erase the block */
    NVMCTRL_BlockErase((uint32_t)nvm_user_start_address);

    /* Wait for row erase  to complete */
    while(NVMCTRL_IsBusy());

    /* Program a page of data */
    NVMCTRL_PageWrite((uint32_t *)pageBuffer, (uint32_t)nvm_user_start_address);

    /* Wait for page program to compete */
    while(NVMCTRL_IsBusy());
}

Library Interface

Non-Volatile Memory Controller peripheral library provides the following interfaces:

Functions

Data types and constants