frequency_meter

Frequency meter

A simple frequency meter. To the SignalAsync_i input, connect the signal whose frequency you want to measure. The measured signal is synchronized with the clock domain in the FPGA using the Synchronizer module, and then the rising edges of this signal are detected using the EdgeDetector module. The measurement method is to count how many edges of the measured signal occur per second. The result is presented on an 8-digit 7-segment display, using the DisplayMultiplex and DoubleDabble modules.

Instantiation

	FrequencyMeter #(
		.CLOCK_HZ(CLOCK_HZ)
	) DUT(
		.Clock(Clock),
		.Reset(Reset),
		.SignalAsync_i(),
		.Cathodes_o(),
		.Segments_o()
	);

Port description

• CLOCK_HZ - Clock signal frequency [Hz].
• Clock - Clock signal, active rising edge.
• SignalAsync_i - Input of measured signal.
• Cathodes_o[7:0] - GPIO pins controlling the display cathodes.
• Segments_o[7:0] - GPIO pins controlling the display segments.

Simulation

Console output

VCD info: dumpfile frequency_meter.vcd opened for output.
===== START =====
Test freq: 123456
Result:    123457
====== END ======
frequency_meter_tb.v:62: $finish called at 1000076500 (1ns)