Hi,
I loaded the RTC_01 example on my Launchpad to do some power measurements and found that
the startup was stuck with an osc fault flag raised loop.
I modified the code to output ACLK on P2.2, I can see a 32.8khz clock. I also tried setting
the 4 different drive strengths, with no change.
Is there a known issue with the FR2433 or the board? Is the example wrong?The clock seems high, but the docs suggest the fault flag should not be raised.
From 5.11.3
fFault,LFXT Oscillator fault frequency (8) XTS = 0(9) 0 3500 Hz
(8) Frequencies above the MAX specification do not set the fault flag. Frequencies between the MIN and MAX specifications might set the
flag. A static condition or stuck at fault condition sets the flag.
(9) Measured with logic-level input frequency but also applies to operation with crystals.
TI Example code for reference
int main(void)
{
WDTCTL = WDTPW | WDTHOLD; // Stop watchdog timer
P2SEL0 |= BIT0 | BIT1; // set XT1 pin as second function
P2SEL0 &= ~BIT2; // set pin to observe ACLK
P2SEL1 |= BIT2; //
P2DIR |= BIT2; //
do
{
CSCTL7 &= ~(XT1OFFG | DCOFFG); // Clear XT1 and DCO fault flag
SFRIFG1 &= ~OFIFG;
}while (SFRIFG1 & OFIFG); // Test oscillator fault flag
P1OUT &= ~BIT0; // Clear P1.0 output latch for a defined power-on state
P1DIR |= BIT0; // Set P1.0 to output direction
PM5CTL0 &= ~LOCKLPM5; // Disable the GPIO power-on default high-impedance mode
// to activate previously configured port settings
