MSP430F47197 flash goes crazy!

But I am still struggling with the following statement.

How I can show the "power loss" on such code?! Meaning that the systems understands that the power went off lets say when "4" turns to "5" and when I switch on again it shows the following message:

"Power went off. The last digit was:"   4

maybe using SVS or other alternatives?

Any idea please?

Because the only thing that can help me is FLASH as it is there and cannot be gone by the "power loss" ... I was going to use a flag but it failed! Well, it is normal! It is written in ram! 

Just curious: why you are doing this? What you want to achieve?

CaEngineer said:

maybe using SVS or other alternatives?

SVMh with interrupt.

Ilmars said:

SVMh with interrupt.

Excuse me I have heard about SVM: Supply Voltage Supervisor but not SVMh! With interrupt? Can you please be more specific?

Dear llmars,

This will be part of an Energy meter where the kWh gets lost by power loss and goes back when I find a way to store the it in Flash and read it from when it MCU goes alive!

CaEngineer said:

Excuse me I have heard about SVM: Supply Voltage Supervisor but not SVMh! With interrupt? Can you please be more specific?

Wel.. I missed that you use 4-series. SVM (unfortunately for you) is present on 5-series.

This still leaves comparator option as voltage detector for you. Well. If you have big enough power supply storage capacitors, you can use ADC too. Or just external power supply supervisor IC connected to IO pin with pin interrupt enabled.

Ilmars said:

Wel.. I missed that you use 4-series. SVM (unfortunately for you) is present on 5-series.

Yes I use MSP430F4  not 5.

As for the hardware-wise perspective of view, I know that I need to detect the voltage where it goes below to a certain voltage or not. And I believe the evaluation module in terms of ADC is already assigned and on my board as well.

As for the code, I will keep sharing my problem that will face later on!

Thank you!

I found something strange!!!

When I have a code with RAM + FLASH together! after power on Reset it shows nothing on the display!!! Whereas, when I run it on RAM only after power on reset I have the value on the screen! Can anyone explain this to me please?

Here is the code as follows.

#include <msp430f47197.h>

void LCD_init(void);          // Definition of LCD initialization
void DelayMs(int Ms);               
void LCD_cmd(unsigned char cmd);     
void LCD_dat(unsigned char byte);       
unsigned short read_flash (unsigned short address);
void erase_flash(unsigned short address);
void write_flash (char value,unsigned short address);
int lengthCal( double len);
long Show(long z );
long Flash(long d);


int main(void)
{
  
  WDTCTL = WDTPW + WDTHOLD;                 // Stop watchdog timer
  
  P7DIR = 0x00; // Redundant
        P8OUT = 0;    // Before set DIR
        P8DIR = 0x07; //P8.2=>EN, P8.1=>RW, P8.0=>RS

        DelayMs(100);  // OR USING  __delay_cycles()
        LCD_init();
        DelayMs(50);

             // ****************************** Just to show "1" on the bottom line of display!*************
       LCD_cmd(0xc0);
       LCD_dat(49);

            // ******************************Flash part of the code *********** Show "1" on the top line of LCD
       LCD_cmd(0x80);
       erase_flash(0x0FFB1); 
       write_flash(1,0x0FFB1);
       read_flash(0x0FFB1);
   
  
}



void erase_flash(unsigned short address)
{
     char *Flash_ptr;                          
     Flash_ptr = (char*) address;             
     FCTL1 = FWKEY + ERASE;                  
     FCTL3 = FWKEY;
     *Flash_ptr = 0;
  //   FCTL3 = FWKEY +  LOCK;
}
void write_flash (char value,unsigned short address)
{
  char *Flash_ptr;                        
  Flash_ptr = (char*) address;            
  FCTL1 = FWKEY + ERASE;                  
  FCTL3 = FWKEY;                          
  FCTL1 = FWKEY + WRT;                      
  *Flash_ptr = value;
  FCTL1 = FWKEY;                           
  FCTL3 = FWKEY +  LOCK;                    
}

unsigned short read_flash (unsigned short address)
{
  char value;
  char *Flash_ptr;
  Flash_ptr = (char*) address;             
  value = *Flash_ptr;
  LCD_dat(value + 48)  ;
  return (value);
}



void LCD_init(void)
{
  LCD_cmd(0x38);    // 8-bit mode 5*8 dots ==> Page 17 of the LCD datasheet: Function Set 
  LCD_cmd(0x0C);    // Blinking display   ==> Page 16 of the LCD datasheet: Display ON/OFF Control
  LCD_cmd(0x06);    // Blinking cursor   ==> Page 15 of NMTC-S0802XRGHS: Entry Mode Set 
  LCD_cmd(0x01);    // Clear Display ==> Page 15 of the LCD 
}

void DelayMs(int Ms)
{
        volatile int i; // To counteract "optimization"
        while(Ms>0)
        {
                for(i=0;i<100;i++);
                Ms--;
        }
}

void LCD_cmd(unsigned char cmd)
{
        P8OUT &= 0xF8; // EN=0,RW=0,RS=0
        P7OUT = cmd;

        P8OUT |= 0x04; // En = 1;
        P7DIR = 0xFF;  // out P7
        
        __delay_cycles(2); //Insurance
        
        P8OUT &= 0xFB; // En = 0;
        P7DIR = 0;     // float P7


        DelayMs(3);
}


void LCD_dat(unsigned char byte)
{
        P8OUT &= 0xF8; // EN=0,RW=0,RS=0
        P8OUT |= 0x01; // change to RS=1
        P7DIR = 0xFF;  // P7 out

        P7OUT = byte;
        
        P8OUT |= 0x04; // EN=1
        
        
        __delay_cycles(2); // Insurance
        
        P8OUT &= 0xFB;  // EN=0
        P7DIR = 0;     //  P7 float


        DelayMs(3);
}

CaEngineer said:

erase_flash(0x0FFB1);