Homework assignment 1 for CSCI 255 -- Spring 2000

This is the first in a series of three small PIC programming assignment. You may do this problem set in groups of three. Turn in one assignment for the group. Include the names of all group members.

The problem

You are to implement an ancient function for the PIC12C671. Your function will receive an eight-bit number, x, in PIC register 20h and also "return" a result in the same register. If x is even, your function should return x/2. If x is odd, your function should return 3*x+1. Here's a C++ function for this task:

long nextnum(long x) {
  if (x % 2 == 1)
    x = 3*x + 1 ;
  else
    x = x/2 ;
  return(x) ;
}

If you need to refresh your knowlege on of PIC assembler code, review CSCI 255 lab 3. By the way, since there is no multiplication or divide operations on the PIC, you'll have to use add and shift.

Turning in

When you have finished your program, FTP the code into your UNCA CSCI account as csci/255/home1.asm.


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