Two Avalon ST Interfaces comparison

hi again

@Ted : I know that there is at least 1 frame delay between the VIP FB input and output (I'm counting on that since I'm gonna compute the difference between an old and the current frame) and I spend a lot of time reading the vip user guide and the avalon spec so I'm pretty sure that what Daixiwen described should work. but it doesn't and it's driving me crazy ! I appreciate your help and I'm desperately in need of a solution

@Daixiwen : I attached the signal tap screen shot :

the two counters count the number of pixel delivered (first counter from the FB source | second counter from the fifo that receives the scaler output)

I hope that would help you figure out my mistake

PS : the used resolution is 800x600 so maximum count is 480000

thank you a lot