In this case we only need to specify the USART which clock speed we want to use (this is nothing but baud rate). The clock signal of serial protocol is implicit, this means that is “Joined with the data stream and there is no need to have separate wire to transmit the clock from one device to another. In serial USART interface, sends the data in little blocks of one byte with one start bit and one stop bit’s. The serial protocol used 2-wire, one to transmit data and other to receive data. The serial protocol is created many years ago. USART can be used to see data on HyperTerminal/serial window of PC also check value of variable and registers at various stages of program. Since there is no display unit on microcontroller. USART is not only use for the purpose of communication but it can also be useful while debugging.
There are many systems such as controllers, sensors & other peripherals communicate with the microcontroller using USART. In AVR ATmega32A, We have built-in hardware support for USART peripheral. USART is most important and widely used peripheral while developing microcontroller based embedded systems. This tutorial is about USART in AVR ATmega32A Microcontroller.
