ECE 331 Spring 2009 Homework 6
Due Friday Mar 6 at the beginning of class.
Show all your work and please try to be neat.
Holdover from HW5
A.9 Textbook: Chapter 2, Advanced Problem 9
Homework 6
1. State Machines
Complete the design of the JK flip flop implementation of the 2-bit state sequencer began in
the part 3 of Lab 5 prelab. Determine the input “glue logic” and construct the final schematic.
2. Write a program segment that initializes memory locations $0100 and $0101 with decimal
numbers 65 and 125, respectively, using appropriate directives.
3. Assuming that accumulator A holds the value $4F:
a) What are the contents of the accumulator after the instruction CMPA #$43 is
performed?
b) What is the value in accumulator A if the instruction BITA #$43 is performed instead?
4. Describe what each of the following directives will do.
a) DATA FDB $C200
b) FCB %11110000
c) FDB $11
5. What numbers are in memory locations $C100 and $C101 after the following program
segment is executed?
LDD #$F00D
LDX #$C100
STD 0,X
BSET 0,X,$44
BCLR 1,X,$11
6. Write a program segment using a looping structure that will copy 6 bytes stored in memory
beginning at $2200 to memory locations beginning at $2400. Make full use of label and
branches to complete this task.
Once you have written this program, assemble them using the 68HC12 assembler that came
with your textbook (or any other similar assembler) and attach the .LST file produced by the
assembler.
C.1 Textbook: Chapter 2, Challenging Problem 1
C.3 Textbook: Chapter 2, Challenging Problem 3