Hands-On RTOS with Microcontrollers

Segger J-Trace

The debuggers with full trace support are referred to as J-Trace. The Cortex Embedded Trace Macrocell (Cortex ETM) is an extra piece of hardware inside the MCU that allows every instruction that has been executed to be recorded. Transmitting all of this information off the MCU requires a few extra pins for clocking the data out (a clock line and 1-4 data lines). Having the ability to trace every instruction the MCU has executed enables functionality such as code coverage, which provides insight into how much code has been executed (line by line). Knowing exactly which lines of code have been executed and when gives us the opportunity to see where a program is spending most of its time. When we know which individual lines of ...