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the generator could start when fpga is loaded. and i just use this pulse to roughly trigger other device. so the accuracy and the jitter won't be a problem for me. so i just need a straightforward way to generate the pulse from the board.
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Look at the "My First NIOS" tutorial that ships with every Terasic board. There is a PIO component used for turning LEDs on/off. Get that working, then modify the design to toggle an I/O with the timing you want. The NIOS tools most likely have a timer software interface; you could use a timer to generate the rising and falling edges, or use two timers, one for each edge.
You can then look for a PWM component. I recall there being one with the BeMicro boards, perhaps the BeMicro-SDK, and use that to generate a more accurate pulse. Its not too hard to develop an Avalon custom peripheral, so you could always look at designing your own. If you get stuck ask questions.
Cheers,
Dave
Honored Contributor
