thankx a lot HenrikOlsson for your help and to be honest, my aim is to generate 3-phase SPWM using PIC16F877 but I started by I understanding single phase SPWM.
I have read the Microchip appliction notes for sine wave with the 16F series chip..http://ww1.microchip.com/downloads/e...tes/00655a.pdf together with the examples given in http://www.picbasic.co.uk/forum/cont...wave-using-DT- interrupts and http://www.picbasic.co.uk/forum/showthread.php?t=14359.
there are number of things which i've not understand from these readings and i'm asking for help from anyone who can help me to understand.these things are:
1)what is purpose/function of TMR1 in SPWM signals generation using PIC16f877
2) which formular was used to generate a lookup table for the sine waveforms
3)what is the purpose of this piece of code and how to get this values from example of http://www.picbasic.co.uk/forum/cont...-DT-interrupts
TMR2 = 16
PR2 = 129

TMR1L = 255
TMR1H = 254