Test: Serial Port Communication - Computer Science Engineering (CSE) MCQ

Some registers like parallel in serial out and serial in parallel out are used to convert serial data into parallel and vice versa respectively.

UART stands for Universal Asynchronous receiver-transmitter and USART stands for Universal Synchronous and Asynchronous receiver-transmitter.

 In data framing in asynchronous means of communication, the data is packed between the start and the stop bit. This is done so as to tell the other computer about the start and the end of the data.

RTS is a request to send control signal which is a control for the flow of data. On the other hand DTR is a Data Terminal Ready control signal which tells about the current status of the DTE.

TTL logic or the transistor transistor logic level is the logic that is understood by the micro-controllers/microprocessors.

In null modem connection the RxD of one is the TxD for the other.

 To make two devices compatible with each other baud rate is mentioned in the serial communication so that the transmission becomes easy and error free.

UART frequency is the crystal frequency f/12 divided by 32, that comes out to be f/384.

SCON register is mainly used for programming the start bits, stop bits and data bits of framing. As it consists of bits like RB8, TB8, SM0, SM1, SM2 etc.

PCON register consists of SMOD bit as its D7 bit, so if we set this bit then the baud rate gets doubled.