M. Fahmy F. wrote:
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Andy:
I am sorry Andy I posted dumm question.. ofcourse we should use UART for asynchronous :)

This is the question revised:
"How do we implement SYNCHRONOUS data transfer (without bit-banging) on standard-8051 device that only have UART port?"

As far as I know all 8051 devices have an USART not an UART, so you don't nescessarily need anything extra for synchronous serial communications. Bot the "S" part is not very flexible. One problem is that the speed is locked to the xtal frequency, so you cannot use an external clock.

Read more in your favorite 8051 datasheet :-)

Best regards,

Mikkel C. Simonsen