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Forum Index : Microcontroller and PC projects : Counter input frequency

Posted: 06:38am
26 Jun 2026
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PhenixRising
Guru

I seem to remember that this was 300KHz on the MX170 but the Picomite manual states 200KHz. Is this reality?

I understand that we have the GP1 option with the RP2350.
 
Posted: 06:52am
26 Jun 2026
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Volhout
Guru

60MHz when using PIO

Volhout
 
Posted: 07:50am
26 Jun 2026
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PhenixRising
Guru

  Volhout said  60MHz when using PIO

Volhout


PIO can go as high as cpuspeed though, right?
 
Posted: 08:24am
26 Jun 2026
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Volhout
Guru

Yes, PIO can RUN at CPU speed. But it needs several instructions to count and pass it to ARM. The best you can do is make it burst count at half the CPU frequency. But controlled count is 1/3 CPU frequency (3 instructions per input cycle).

So if you clock the CPU at 300+ MHz you could count up to 100MHz.

But.... can the RP2040/2350 input handle 100MHz. The input pin and the PCB routing become critical at frequencies above 50MHz. And the PAD driver (silicon inside the chip)...can it handle 100MHz.

Volhout
Edited 2026-06-26 18:27 by Volhout
 
Posted: 10:50am
26 Jun 2026
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PhenixRising
Guru

Oh I'm only looking at <2MHz. Just curious about the 60MHz number.
 


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