connecting avr atmega32 to shift register using USART?

Question

I want to connect ATMEGA32 microcontroller to a shift register using USART via TXD pin, the shift register then performs serial to parallel conversion on the received data. but as you know, the shift register needs clocking , this clocking is fed via the microcontroller at baud rate frequency via XCK pin (here the USART acts as master synchronous clock generator). My problem is that i don't know how to get these clock signal out of XCK, so how to do that???

thanks

Answer 1

RS-232 is self-clocking (fix baud rate) - it typically uses x16 clock supplied to a UART which syncs to the incoming data start bit edge. Rather than use a bare shift register you would probably be better off just using a simple UART chip as your serial to parallel converter - it would save a lot of effort.