MSP430FR2355: Low frequency crystal not working.

glen worstell

Part Number: MSP430FR2355
Other Parts Discussed in Thread: MSP430FR2311,

I have a launchpad with a 32768 crystal and another with a 38400 crystal. With the MSP430FR2311 they both work perfectly.

With the MSP430FR2355 I am unable to get ACLK to work with the crystal. Dual trace scope verified that the crystals are oscillating at the correct frequency,

but ACLK is running at the REF0 frequency (close to 32700 Hz).

Here is the code I use to show ACLK:

; setup ACLK -result is about 32708 Hz, should be 38400
bis.b       #BIT1, &P1DIR
bis.b       #BIT1, &P1SEL1
bic.b       #BIT1, &P1SEL0
bic       #BIT8|BIT9, &CSCTL4
; bis       #BIT13, &CSCTL6           ; disable auto switch to REFO
; don't see ACLK if above is set. This is correct behavior.

Suggestions greatly appreciated.

over 6 years ago

0 Eason Zhou over 6 years ago

TI__Mastermind 40195 points

Hi,

You mean you can't see ACLK output?

Do you add this asm code:

            ; Disable the GPIO power-on default high-impedance mode
            ; to activate previously configured port settings
            bic.w   #LOCKLPM5,PM5CTL0

Here is the code as a reference.

msp430fr235x_CS_05.asm

Eason

0 Eason Zhou over 6 years ago

TI__Mastermind 40195 points

Is it solved?

Eason

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MSP430FR2355: Low frequency crystal not working.