hi, I would like to program a 8051 microcontroller but I want to use the USB port instead of the I2C bus, can anyone please tell me how to do it? thanks.
There are several 8051 derivatives with on-chip USB - use the parametric search in the Device Database on this very site. There are also several chips available to interface USB to an 8051 (or other microcontroller of your choice) eg, see http://www.8052.com/forum/read.phtml?id=44733