User manual

 iSYSTEM, September 2014 20/23
Example 3 Qualifier Settings
Start the trace and run the application from reset on. After Type_Simple() is executed five times, the
trace will trigger and normally display the program around the trigger message. Let’s analyze the trace
record. It’s possible that the trace record will contain the overflow messages. That happens due to the
enabled data trace. Occurrence of overflows depends on the code, which can generate an arbitrary
number of data accesses. If the CPU accesses the data very often in a short time, it can produce such
amount of messages that the CPU internal Nexus trace FIFO buffer can no longer handle. If that
happens, an overflow message is sent out signaling the external trace hardware that the trace
information is lost and no longer valid. From that moment on the debugger can no longer reconstruct
the program flow properly until the trace FIFO buffer is flushed and a synchronization message is
broadcast. There are two solutions for this problem presented below.