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PPM? Pulse Per Minute, Pages Per Minute, Peak Program Meter, Perl Package Manager, ...?

Assuming this was a type and should have been PWM, then what is the range of frequencies and duty cycles? How about the voltage level? How often do the "hyperterminal" need to be updated? What sort of accuracy do you need? What is to be displayed frequency, duty cycle, on/off time, or something else? How fast is your CPU clocked? Must it be a GPIO pin and not one of the hardware interrupt pins? What resources are free for use like timers? What is the source of the 'PMM' signal? Have you read the datasheet? What toolchain are you using? What is your experience level?

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