I would like to simulate a pulse train with maximum 2.5 micro second width.
So you would like 2.5us positive pulses. What frequency? How many pulses ... or do you just want to start/stop continuous pulses through software commands?
General related information in the Waveform Generation App Note:
Can I control the amplitude of the pulse? I have tried and did a pulse with 10 micro seconds and ampiltude of 1V, I would like it to be 1.5V ish.
If you need variable amplitude, you can use the DAC, but that would not work for your quick times. For your quick times, you would create a 0/3.3V waveform on a digital output, and use that waveform to control a switch of some sort that is gating the variable voltage from a DAC.