Hi gurus,
Please forgive the simple question - I'm trying to wrap my head around this.
I have a (fast) clock coming from an external source. I want to measure its frequency. The thinking is to feed that clock into an external capture timer pin, eg TACLK or TA0, for some fixed period of time (eg 50 ms). Then take a look at how much the counter register has incremented. (And probably add an interrupt to count overflows.)
What I cannot quite work out is the maximum input frequency the TACLK or TA0 pin will handle. For example, on the MSP430x22x2 datasheet, it says:
Timer_A Clock Frequency (TACLK): 16 MHz max
Timer_A Capture Timing (TA0): 20 ns min
A 20 ns period corresponds to 50 MHz.
Am I correct in believing that 20 ns (TA0) is only for a single edge, not a clock per-se? So in my case, where I want an external clock to increment an asynchronous counter, I have to use TACLK which is limited to 16 MHz?
I'd like to count up faster if I could - 50 MHz would be nice.
Thanks.