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MSP430FR2433: How many cycles to toggle a GPIO

pathfinder
Genius 12790 points

Part Number: MSP430FR2433

Support,

I have MSP430FR2433 @ 16MHz and I'm trying to figure out how fast I can toggle a GPIO pin?  I am going to dig into the assembly and do not have a scope but figured I'd ask.

Can someone point me to specific example where a timer is set to toggle a GPIO at different frequencies?  I'm concerned that this method will be very complex from the MSP core point of view to setup different pulse waveforms.

Regards,

Marc

  • 0
    Guru 34973 points

    For port toggling by executing code in assembler on CPUvX2, port must be read (2 cyles), toggled (1 cycle) and write back (3 cycles). With recorded sequence, fired DMA can copy data to port in 2 cycles (1 cycle for read and 1 cycle for write). However CPU can not work together with DMA. I don't know if topic device is with DMA module. Easiest way is to do it with timers, and (if I remember right) it can go up to MCLK/2.

  • 0
    TI__Mastermind 30545 points

    Hey Mark,

    What are you trying to do?  Are you trying to figure out exactly how many clock cycles it takes to toggle the gpio or the actually toggle speed limit of the GPIO?

    For the former, I think zrno provided some good info. 

    As for limits of the GPIO, this is defined in Table 5-11.  The GPIOs can toggle at least 16MHz and output the max system clock.  

    Thanks,

    JD

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