Default PMMCOREV value of CC430F6137/Chronos eZ430

The CC430 Family User's Guide SLAU259B shows that the PMMCOREV bits in Power Management Module Control Register 0 (PMMCTL0) are cleared by a Brown Out Reset (BOR).

Therefore, if a Power On Reset (POR) or Power Up Clear (PUC) restarts the CC430F6137 the PMMCOREV bits will maintain their value prior to the reset. 

The System Resets, Interrupts, and Operating Modes, System Control Module (SYS) section of the User's Guide explain the difference between BOR, POR and PUC.

Does the code in the CC430F6137 change the PMMCOREV bits sometime from main?

Also, when debugging programs I am not sure which reset method is used, but in the past have got confused due to some registers settings only cleared by a BOR being left at their settings from the previous program that was run.

Hi Chester,

thanks you for your answer.

I have tested it without the debugger aswell by removing the battery, which results in a bor reset. My software sets PMMCOREV to 1 anyways (and i verfied that).

Well this is odd. I assume that you dont use the original TI firmware, because PMMCOREV is always set to 3 before the test_mode call.

I did the same thing and used the rFBsl mode without an AP and the register field still has initially the value 3. As i said my code checks the register value right at the beginning of the main function, so the firmware does not change any register unless IAR adds some code that changes this register before the main is called.

I use IAR 5.10.6, several 868 MHz Chronos, which show the same result and a modified version of the original 1.1 chronos project.

mark sonnentag said:

Well this is odd. I assume that you dont use the original TI firmware, because PMMCOREV is always set to 3 before the test_mode call.

int main(void)
{
   volatile u8 ps;
   int initial_PMMCTL0 = PMMCTL0;  // Added
   int initial_SYSRSTIV = SYSRSTIV; // Added

   // Init MCU 
   init_application();

   // Assign initial value to global variables
   init_global_variables();

   // Branch to welcome screen
   test_mode(initial_PMMCTL0, initial_SYSRSTIV); // Added parameters

   // Main control loop: wait in low power mode until some event needs to be processed
   while(1)
   {
      // When idle go to LPM3
      idle_loop();

      // Process wake-up events
      if (button.all_flags || sys.all_flags) wakeup_event();

      // Process actions requested by logic modules
     if (request.all_flags) process_requests();

     // Before going to LPM3, update display
     if (display.all_flags) display_update(); 
    } 
}

Modified function prototype in test.h:

extern void test_mode(int initial_PMMCTL0, int initial_SYSRSTIV);

void test_mode(int initial_PMMCTL0, int initial_SYSRSTIV) // Added parameters
{
   u8 test_step, start_next_test;
   u8 * str;
   u8 i;

   // Disable timer - no need for a clock tick
   Timer0_Stop();

   // Disable LCD charge pump while in standby mode 
   // This reduces current consumption by ca. 5µA to ca. 10µA
   LCDBVCTL = 0;

   // Show welcome screen
   char test[5] = "0000";
   test[3] = (initial_PMMCTL0 & 3) + '0';
   display_chars(LCD_SEG_L1_3_0, (u8*)test, SEG_ON); // Displays PMMCOREV
   //display_chars(LCD_SEG_L1_3_0, (u8*)"0430", SEG_ON);
   display_chars(LCD_SEG_L2_2_0, (u8*)itoa(initial_SYSRSTIV, 3, 0), SEG_ON); // Displays SYSRSTIV in decimal
    //display_chars(LCD_SEG_L2_4_0, (u8*)"CC430", SEG_ON);
   display_symbol(LCD_SEG_L1_COL, SEG_ON);
   display_symbol(LCD_ICON_HEART, SEG_ON);
   display_symbol(LCD_ICON_STOPWATCH, SEG_ON);
   display_symbol(LCD_ICON_RECORD, SEG_ON);
   display_symbol(LCD_ICON_ALARM, SEG_ON);
   display_symbol(LCD_ICON_BEEPER1, SEG_ON);
   display_symbol(LCD_ICON_BEEPER2, SEG_ON);
   display_symbol(LCD_ICON_BEEPER3, SEG_ON);
   display_symbol(LCD_SYMB_ARROW_UP, SEG_ON);
   display_symbol(LCD_SYMB_ARROW_DOWN, SEG_ON);
   display_symbol(LCD_SYMB_AM, SEG_ON);

I don't have a full IAR compiler license to try, and if I use IAR Kickstart to try and compile the "868MHz - Limited IAR Kickstart" get linker errors.