Pwm???

hello folks,
I would like to know how to use the PWM, in particular how can I initialize the assembly code???
I need of the PWM because I have to generate an analogue signal, then I would to know How have I to change the duty cicle(assembly code)???
my microcontroller is an ATmel
How many channels of PWM can I do???
thanks to all


P.S.:I'm not English... I'm sorry to errors

Which "ATmel"?

Do you mean software PWM?

If you meant software PWM then here are some tutorials..
**broken link removed**

If you are using Atmel AVRs then i would suggest hardware PWM..