Hi Rauf,

I'm using a Cygnal C8051F226 with a ScanLogic HS811HS USB interface chip to connect to the PC. The combined price is around $10. The USB interface uses 14 I/O lines of the 8051. I'm clocking the 8051 at 24MHz, and have been passing 200kBytes per second, without problem, though you could pass more. Scanlogic provides drivers, and some fairly bad example code, though I would pass on the non-vendor specific portions of my usb code. I know that this isn't a single chip solution, but It should be a reasonable alternative--I started out by connecting eval boards for each chip, and modifying the code provided by Scanlogic--it took about 3 weeks to get data flowing.

Best Luck,

Josh