main_nvm_test.c

#include "sam.h"

#include "system.h"
#include "uart.h"
#include "flash.h"
#include "bitstream.h"

#include "print.h"

#define FLASH_DATA_START (0x00020000UL)
#define FLASH_DATA_END   (0x00040000UL)

int main_nvm_test()
{
    // Set up system
    system_init();
    
    // Set up UART
    uart_init(9600);
    
    // Enable the UART
    uart_enable_interrupts();
    uart_enable();
    
    uint32_t* nvm_val = (uint32_t*) (0x00020000UL);
    
    print_cstring(uart_write, "main_nvm_test.c\r\n");
    print_cstring(uart_write, "\tInitial NVM value: ");
    print_hex32(uart_write, *nvm_val);
    print_cstring(uart_write, "\r\n");

    // Clear the NVM row
    // TODO
    
    // Enable manual writes to NVM
    NVMCTRL->CTRLB.bit.MANW = 1;
    
    // Print ADDR
    print_cstring(uart_write, "\tADDR before access: ");
    print_hex32(uart_write, NVMCTRL->ADDR.reg);
    print_cstring(uart_write, "\r\n");
    
    // Write a special value to NVM
    *nvm_val = 0xDEADBEEF;
    
    // Print ADDR
    print_cstring(uart_write, "\tADDR before WP: ");
    print_hex32(uart_write, NVMCTRL->ADDR.reg);
    print_cstring(uart_write, "\r\n");
    
    // Commit to NVM (manual write)
    NVMCTRL->CTRLA.reg = NVMCTRL_CTRLA_CMDEX_KEY |
                         NVMCTRL_CTRLA_CMD_WP;
                         
    while(NVMCTRL->INTFLAG.bit.READY == 0);
    
    if (NVMCTRL->INTFLAG.bit.ERROR == 1) {
        NVMCTRL->INTFLAG.bit.ERROR = 1;
        print_cstring(uart_write, "\tINTFLAG.ERROR set.\r\n");
    }
    
    // Print ADDR
    print_cstring(uart_write, "\tADDR after WP: ");
    print_hex32(uart_write, NVMCTRL->ADDR.reg);
    print_cstring(uart_write, "\r\n");
        
    print_cstring(uart_write, "\tNVM value after WP: ");
    print_hex32(uart_write, *nvm_val);
    print_cstring(uart_write, "\r\n");
    
    // Clear NVM...
    // TODO how?
    
    // 1. Update ADDR by accessing memory
    *nvm_val = 0x00000000;
    
    print_cstring(uart_write, "\tADDR before ER: ");
    print_hex32(uart_write, NVMCTRL->ADDR.reg);
    print_cstring(uart_write, "\r\n");
    
    // 2. Clear whatever row ADDR points to...
    NVMCTRL->CTRLA.reg = NVMCTRL_CTRLA_CMDEX_KEY |
                         NVMCTRL_CTRLA_CMD_ER;
    
    print_cstring(uart_write, "\tNVM value after ER: ");
    print_hex32(uart_write, *nvm_val);
    print_cstring(uart_write, "\r\n");
    
    // Try another write...
    
    *nvm_val = 0xDEFEC8ED;
    
    // Commit to NVM (manual write)
    NVMCTRL->CTRLA.reg = NVMCTRL_CTRLA_CMDEX_KEY |
                         NVMCTRL_CTRLA_CMD_WP;

    while(NVMCTRL->INTFLAG.bit.READY == 0);
    
    if (NVMCTRL->INTFLAG.bit.ERROR == 1) {
        NVMCTRL->INTFLAG.bit.ERROR = 1;
        print_cstring(uart_write, "\tINTFLAG.ERROR set.\r\n");
    }
    
    print_cstring(uart_write, "\tNVM value after second CMDEX: ");
    print_hex32(uart_write, *nvm_val);
    print_cstring(uart_write, "\r\n");
      
    return 0;
}