User manual

MPLAB

REAL ICE

™

In-Circuit Emulator User’s Guide

4.13.2 Tracing a Line of Code

To trace a line of code:

1. Remove the log macro line from code, i.e., highlight it and hit <Delete>.

2. Highlight or click on the following line of code:

counter++; //increment counter

Right click to select “Insert C Line Trace” from the pop-up menu. This causes the

following macro line to be inserted above the selected line:

__TRACE(id);

where id is a line trace number auto-generated during the build.

3. Rebuild the project (Project>Build All

4. After rebuilding, a Warning dialog will ask, “File has been modified. Do you want

to reload?” (if you have not already disabled this dialog.) Click Yes. When you

examine your code, you will find that the log id has been replaced with a unique

number.

5. Reprogram the device (Debugger>Program

6. Run the program until it halts at the breakpoint. Repeat this three times.

7. Select View>Trace

to view the trace data (Section 11.3.11 “Trace Window”) or

right click and in the Trace window and select “Reload”. You should see address

values logged in this window. To see the related code in the lower portion of the

window, you may need to click on a logged value in the upper portion of the win-

dow.

FIGURE 4-21: VIEW TRACE WINDOW – TRACE LINE

4.13.3 Setting the Size of the Trace Buffer

In this tutorial, a breakpoint was used to ensure that the trace buffer did not overflow

with values from an executing program. A “for” instead of “while” loop could be used as

well to control the number of trace samples.

To set the size of the trace buffer:

1. Select Debugger>Settings

, Trace tab.

2. Enter a value for the trace buffer, not to exceed the maximum specified on this

tab.