ECE-3120
Spring 2008
LAB 4 – Min/Max Program
2/27/08 Page 1 of 3 Lab 4
The purpose of this lab is to reinforce your basic programming skills with the 68HSC12
using program loops, arrays, comparisons, and arithmetic instructions.
PRE-LAB:
Prepare pseudocode and the first draft of the program and calculate the expected results
by hand (both decimal and hex). This must be completed before coming to the lab and
shown to the lab instructor at the start of the lab session. Note: The Pre-Lab must be
typed into a proper *.ASM source file, following our standard Program Format
requirements.
Approved: Lab TA _____________________ Date ____________
PROGRAMMING ASSIGNMENT:
Write a fully-commented program for the HC12 board, following our standard Program
Format requirements (http://iweb.tntech.edu/rhaggard/3120s08/Program_Format.htm),
including appropriate directives and labels for memory operands and constants, called
Minmax.asm. It must use a program loop and comparisons for most of the work. The
program should do the following:
• Be able to process any array of 1 to 255 signed data words as follows. Each
data word can have a value between -32768 and +32767. This means that the
program should be able to handle any size array in this range, with any set of
values, by changing ONLY the directive that creates the array values, without
modifying any instructions or other directives.
• The size of the array cannot be stored as a pre-defined constant. A zero value
in the array is a delimiter (special flag value) that means that you have
reached the end of the array, so stop all processing at this point. This is
another way to terminate a loop, without using a fixed number inside your
program (or in a directive). The program must not include the delimiter of
zero in calculating any of the numerical results.
• Count the number of array elements that are exact multiples of 5.
• Search through the array, looking for the maximum (most positive) and
minimum (most negative) numbers. Also give the array index of the
maximum number.
• The code must start at $1000.
