MSP430F5529: Can't get XT2 16Mhz to run CPU

Jerry Bucci0

Part Number: MSP430F5359

Hi,

I have a 16Mhz crystal on XT2IN and XT2OUT . I see 16MHz on the scope so I know the oscillator is working. If I run a simple counting timing loop and toggle a pin, I see no change in the CPU speed from the default clock cycle. I imagine it's a register setup issue. Please help.

Thanks

My setup code for switching MCLK to XT2 is;

P7SEL |= 0x0C; // set XT2in out as osc mode bits 2,3
P7DIR |=0x08; //bit 3 out
P7DIR &=0xFB; //bit 2 in
UCSCTL6 &=0xFEFF; //XT2 on
UCSCTL4 |=0x0005; //101b = XT2 16Mhz MCLK source

over 7 years ago

0 Cameron LaFollette over 7 years ago

TI__Genius 14875 points

Hi Jerry,
XT2 in out is on P5.2 and P5.3, and I dont see that you've set those up. We actually have example code that does what you're trying to do, check it out at: dev.ti.com/.../

0 Jerry Bucci0 over 7 years ago

Prodigy 30 points

Sorry- the part I'm using is the MSP430F5359, where the XT2 pins are P7,2&3. I couldn't figure out easily how to edit my post but i will.

0 Jerry Bucci0 over 7 years ago in reply to Jerry Bucci0

Prodigy 30 points

I got it working using the demo software, but it says you can;t use the LFXT1 clock also? I need the 32Khz clock for the RTC? Can't both clocks be used?

0 Cameron LaFollette over 7 years ago in reply to Jerry Bucci0

TI__Genius 14875 points

Hi Jerry,
Here's the example code for that part dev.ti.com/.../

I think it's an issue with your oscillator fault flags. Check the code example for how to handle them.

0 Cameron LaFollette over 7 years ago in reply to Jerry Bucci0

TI__Genius 14875 points

Both clocks can be used. That comment is just for that example where LFXT is not connected.

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MSP430F5529: Can't get XT2 16Mhz to run CPU