The purpose of this lab is to familiarize the student with assembly language program design. You may work in pairs and submit a group report.
This lab is based on a lab developed by Dr. S. Barnicki.
In this lab, you will design, code, assemble, link, simulate, download, and run a program. The program you will be writing is a bouncing LED program (the "Knight Rider" effect). Start on the left side of the eight-LED display, and turn on the leftmost LED (remember, you send a 1 (one) to turn on an LED). Then wait, and turn the next LED to the right on and the leftmost one off. Continue moving the lighted LED to the right. After the LED on the far right is on, move the lighted LED position to the left. Repeat this forever. Never have all the LEDs off at any time. You are not allowed to use a look-up table (like the example in class) in this program. You must use another algorithm to generate the LED pattern. Use the time delay (wait) routine discussed in class.
All the downloadable programs are available at the tools page.
You can use the LED demo program from class as a starting point. The instructions you will use for this project include the JSR (or BSR) instruction to call the wait function. When moving the on LED position to the right, use a ROR instruction. The carry flag can then be tested (perhaps with the BCS or BCC instruction) to see if the bit you are shifting was moved into the carry bit. To move to the left use a ROL instruction. Remember, the LEDs are active high on the F0x11; a zero (0) turns an LED off, and a one (1) turns a LED on.