Ahmed Barakat wrote:
-------------------------------

but for reading how the MC controller will now which location the PC want to read while there's no lines for address or simply if you want to do that (read from it and it's also a problem for writting :which location to write to) what will you do?


You don't seriously think that yo have direct memory access using a UART, do you?

Your PC sends 8 data-bits to your microcontroller. What your microcontroller does with it, is determined by the program you wrote. It is up to you (read your program) to do something meaningful with the data you received. For your microcontroller is just 8 bits that happen to be present in the SBUF...


Check the IIC (or I2C) protocol for an example of serial communication. It has a way of sending address and data.Maybe you also want to check the CAN protocol, but someone else will have to give you the details... (unless you search for it on this forum of course)

Regards
Patrick De Groote