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Atomic counter is a frequency counter designed for an accurate frequency measurements. It has a PPS output from GPS used as a frequency normal 1). Its construction is now implemented in two variants:
- ACOUNTER01A - Produced using FPGA board
- ACOUNTER02A - Produced using microcontroller PIC16F887 and several other modules.
Accuracy of both variants is determined by a used GPS and a quality of incoming signal. However, generally, each measurement needs to be averaged over a longer time period, because the time stamps only have a short-term accuracy in order of tenths of ns. Individual measurements can therefore have a relatively wide Gaussian scattering, which has to be eliminated by averaging.
Using clkgen module, a functionality up to at least 850 MHz has been verified. However, as the divider's input clkdiv works up to 3 GHz, we expect the counter to be operational up to this frequency.