In this section we are going to:

- Move our "turn red LED on" code into a function

- Build 3 functions, one for each LED

- Debug: Step Over the first function while you Step Into the remaining 2 functions called from main() while observing the registers change

Create a function for the red LED:

Here is an example of putting the red LED code into a function called rL_on():

Create two more functions:

Now we'll build two more functions, one for the yellow LED [yL_on()] and one for the green LED [gL_on()]:

Call the functions:

Next we'll call these 3 functions, rL_on(), yL_on() and gL_on() from our main() function:

Reorder your code so main() is last:

The ZDSII IDE compiler is particular: it wants the functions called by main() to precede main(). Failure to do so will result in an error. So here's what the final program could look like:

Stepping through Breakpoints:

If you're going to debug and step through the code, consider using Insert Breakpoint     at each of the functions in main as shown below.

Under Debug, choose Connect to Target. Under View | Debug Windows, enable Special Function Registers three times. Change the defaults of AES to GPIO Ports A, B and C.

Once you press Debug | Go you can watch each port's values change while stepping.

Step over an existing Breakpoint:

Because you've already watched Port B's registers change, you may want to skip over it and check out Port C's registers instead.  To do so requires the following:

- Insert Breakpoints for all functions under main()

- Build | Build

- Debug | Connect to Target

- Position your flashing cursor on the first function, rL_on() and press <CTRL> <F10> to Run to Cursor. You should see a yellow right-facing arrow within the first red breakpoint

- Now we'll skip over this function and move onto the next using <F10> or Step Over

- Press <F11> to Step Into the function itself. Continue to press <F11> to advance through each line of code in yL_on() as you watch the registers change on the right side of your screen