MSP430F6779A: Startup from AUXVCC1

Hello,

Some interactions among fSYS, VCORE, VDSYS, SVMH , and AUXxLVL must be considered. Please see the section 4.2.5 in MSP430x5xx and MSP430x6xx Family User's Guide (Rev. Q) for more details.

Thanks for responce.

I decided to try example 3 from 4.2.13.3 and wrote simple main function:

void main(void)

{

StopWatchDog; // stop internal watchgog

PMMCTL0_H   = 0xA5;

PMMCTL0_L  &= 0xFC;  // PMMCORELEV = 0

SVSMHCTL_L &= 0xF8;  // SVSMHRRL = 0

SVSMHCTL   |= SVSMHACE + SVSHE; // enable automatic control

SVSMLCTL   |= SVSMLACE; // enable automatic control

AUXCTL0_H   = 0xA5;

AUXCTL2     = 0x0001;// AUX0LVL=1,  AUX1LVL=0, AUX2LVL=0

AUXCTL0_L  &= 0xFE;  // unlock AUX

InitLCD();          // init LCD

DisplayAll();      // display all segments

for(;;);

}

I intended to set automatic hardware controlled mode.

It works when I apply 3.2V to DVCC. It does not work when I apply 3.2V to AUXVCC1. 

I tried other configurations for SVM and AUX. Nothing helps.

Accordingly to section 4.2.1 chip must start from AUXVCC1 when DVCC is not present.

I wonder if core starts at all. What voltage should be at DVCC when chip starts from AUXVCC1?

What's the core voltage? If the supplies (DVCC/AVCC and AUXVCC1) differ by less than 100 mV, the selected supply can be either DVCC/AVCC or AUXVCC1. The supply with the higher voltage is selected only if the difference is greater than 100 mV.