Lecture 2 - Serial Comms

Question 1

What IO port do the TXD and XD pins reside?

Answer 1

Port D
TXD = D.1
RXD = D.0

Question 2

What registers are used to set the baud rate?

Answer 2

UBRRH, UBRRL

Question 3

In synchronous serial communication are the clocks of the sender and receiver synchronised?

Answer 3

Yes

Question 4

In asynchronous serial communication are the clocks of the sender and reciever synchronised?

Answer 4

No

Question 5

What is the formula to find the value for the UBRR regsiters (baud rate)?

Answer 5

UBRR = [((system clock freq.)(16*baudRate)] - 1

Question 6

Steps involved in sending/receiving formatted strings:

Answer 6

Write two functions to send and receiver a character via serial port.
In main function call fdevopen().
Use printf/scanf as usual