from 160 000 000 chips total of gen3.
whatt?! where did you get those numbers?

Its upper limit from :
1) What is the order of magnitude of 3rd generation chips ASICMiner anticipates to sell (total / first batch / first 3 months)?
re 1) Order of magnitude: Depending on fab capacity. Total target is 10k to 40k wafers, relying on competitors, Bitcoin price, and other factors. A wafer is rated at 40 TH/s.
also I see that you're calculating 0.5$ profit per Gh/s ... selling price is from 0.49$ (unlikely for first batches) to 0.99$ (more likely), production costs -0.2$ Gh/s, put this into sheet
so basically, the lower and higher targets takes us between 1 and 4,1 BTC divs per share...