MSP430FR6047: Issue with HSPLL Unlock Error

Hi Hao,

It's great to hear from you again. Regarding our custom board, the USSXTAL uses a crystal oscillator instead of a ceramic resonator. For this, I have modified the following settings in uss_userconfig.h:

I have two questions:

1. According to the user manual, if a crystal oscillator is used, the HSPLLUSSXTCTL.OSCTYPE bit in the HSPLLUSSXTCTL register should be set to 0. Does the above code automatically implement this change, or do I need to manually modify the register value?

2. Does the USSXTAL only operate when transmitting waveforms? If so, I observed a brief high-frequency signal on the oscilloscope. Does this indicate that the USSXTAL is functioning correctly?

.

Looking forward to your clarification.

"I'd like to share the latest progress with you. I've replaced the crystal oscillator with a ceramic resonator (model AWSCR-8.00CV-T) for the USSXT to align with the EVM board configuration. The host computer is now reporting no errors.

However, I'm puzzled by one finding: While the datasheet indicates that HSPLL supports crystal oscillators as clock sources, why is the crystal oscillator unusable in the water_demo application? Even after modifying the configuration files, it still doesn't work."

Hi,

I believe the issue has been identified. I flashed the HSPLL example code from the following link:
https://dev.ti.com/tirex/explore/node?node=A__ACQ2..dUrB7EMaOXgN0m8Q__msp430ware__IOGqZri__LATEST

As mentioned earlier, the code runs normally. I checked the output pin of the crystal oscillator and observed an 8MHz waveform, confirming that the oscillator circuit is functioning correctly.

However, after flashing the official code and modifying the USSXT type in userconfig.h, the oscillator output pin no longer shows the 8MHz waveform.

I suspect that the HSPLL initialization configuration in Water_Demo differs from the example code. Could this be a bug? It appears that Water_Demo does not support using the crystal oscillator as USSXT, even after modifying the USSXT type in userconfig.h.

This is the initialization statement in the hspll example code

void HSPLL_init(void)
{
    // Configure USSXT Oscillator
    HSPLLUSSXTLCTL = OSCTYPE__CRYSTAL |  USSXTEN;

    // Set up timer to wait in LPM for crystal stabilization time = 4096 clocks for crystal resonator.
    // For 8MHz XTAL, 4096 clocks = 512us. Using VLO = 9.4kHz, wait 5 timer clock cycles = 532us.

    TA4CCR0 = 5;
    TA4CCTL0 = CCIE;                        // Enable Interrupt
    TA4CTL = TASSEL__ACLK | TACLR | MC__UP; // Timer sourced from ACLK (VLO), clear timer
    __bis_SR_register(LPM3_bits | GIE);     // Enter LPM3 w/interrupt
    __no_operation();                       // For debug

    // Check if oscillator is stable
    while((HSPLLUSSXTLCTL & OSCSTATE) == 0);

    // Output oscillator on pin
    HSPLLUSSXTLCTL &= ~XTOUTOFF;

    // Init PLL
    // Use the PLLM setting to get 80MHz output from our 8MHz input
    // Equation: PLL output clock frequency x 2 = input clock frequency x (PLLM+1)
    // Input clock frequency = 8MHz
    // Desired PLL output clock frequency = 80MHz
    // PLLM = 19
    HSPLLCTL = PLLM4 | PLLM1 | PLLM0 | PLLINFREQ; //PLLM = 19, PLL input frequency > 6MHz

    // Power up the UUPS to start the PLL
    UUPSCTL |= USSPWRUP;

    // Wait for UUPS to power up
    while((UUPSCTL & UPSTATE_3) != UPSTATE_3);

    // Wait for PLL to lock
    while(!(HSPLLCTL & PLL_LOCK));
}