Do you want the 89c52 to be USB host or USB slave?
If you want to connnect the 89c52 to a PC you can use a USB to RS232 converter like FT232BM from www.ftdichip.com or PL-2303 from www.prolific.com.tw or the new CP2101 from **broken link removed**
now i tell u problem i wanna send 3 adc data to pc via usb
i done all other jobs but iam biggner in usb as u suggested me
r these converter help me to communicate with 89c51 that i separatly get
each adc data and handel them
The easiest way to do this is to use one of the three USB to RS232 converters I suggested.
You connect USB from the IC to the PC and connect RS232 RX and TX from the IC to the 89c51 UART.
These three IC's acts as a virtual RS232 port at your PC. You have to install a driver at your PC. You can get the driver from the IC vendor.
Now you can just send and receive RS232 data a your virtual com port.