can any one please suggest me about bellow question
which microcontroller having two inside zero crossing detector modules inside ?

 

Zero-crossing detection is not something that μC's do natively.
Most applications that you will find are for power-line synchronization, where the input-voltage must be reduced and possibly filtered.
Only then does the microprocessor see it, presented to an input pin and detected (most reliably ) by an interrupt. Therefore, any μC with two external-interrupts will do it.

Why do you need two ZCD's?

 

The 16LF1709 does have ZCD

You could use 2 PICs, and link them up with software serial port.

I think it only has one ZCD. Well, theres normally only one mains? Even if you have more phases, they are synchronous. Or do you deal with AC generated off mains?

 

You could need two if you want to find out the phase difference between voltage and current.

 

ya which microcontroller having two zcds

 

You could need two if you want to find out the phase difference between voltage and current.

For me its easy to link up PIC, 2 or more, I have experience with it. Usually it only needs slow link.
Software synchronous is also fast, can use 4 bits if neccessary.

 

i didnt understand