FAQ

Software-based tracing always means some processing overhead, where the exact amount is f x e, where f is the average event frequency and e is the average execution time for storing an event. This is very dependent on your application and processor. The more RTOS calls, the larger overhead. The faster processor, the less overhead. Let's put in some [...]

If asserts are enabled the recorder configuration (trcConfig.h), this error is generated in uiTraceGetPriorityProperty when a task has an "object handle" value larger than expected. Our FreeRTOS recorder assignes each task an 8-bit "object handle" (the "id" parameter in uiTraceGetPriorityProperty), which should be in the range [1..NTask]. The NTask constant is defined in trcConfig.h and [...]

Our Tracealyzer versions for microcontroller RTOS uses Percepio's own recorder library, which uses separate definitions for critical sections within the recorder. This since the standard critical sections offered by some RTOS kernels, like portENTER_CRITICAL/portEXIT_CRITICAL in FreeRTOS, might not safe to use from interrupt (kernel) context. Some recorder functions are called both from task-level and interrupt-level [...]

The Tracealyzer support for FreeRTOS, SafeRTOS and Micrium relies on Percepio's own recorder library. This can be used on most processors and contains ports for several common processor families, including: Arm Cortex-M devices, e.g., STM32, NXP LPC series, Renesas Synergy, etc. Arm Cortex-A9 devices, e.g. Xilinx Zynq. Renesas RX600 series Microchip PIC32 series Atmel AVR32 [...]

(This answer is only applicable for Percepio's own recorder library, used for e.g. FreeRTOS, OpenRTOS, SafeRTOS and Micrium µC/OS) Streaming mode As for v4.1.6, Tracealyzer supports streaming via SEGGER J-Link, IAR I-Jet and Keil ULINKpro/ULINKplus. Streaming is also possible in other ways, e.g. using USB CDC or a network connection. IAR users can find more [...]

(This answer is only applicable for Percepio's own recorder library, used for e.g. FreeRTOS, OpenRTOS, SafeRTOS and Micrium µC/OS) It depends if you are using snapshot or streaming mode. Snapshot mode requires a decent RAM buffer if you want a long trace. A RAM buffer of 5-10 KB can give a trace of 50-200 ms, depending on [...]

(This answer is only applicable for Percepio's own recorder library, used for e.g. FreeRTOS, OpenRTOS, SafeRTOS and Micrium µC/OS) The below table shows an example, using version 2.5.1 of the recorder library when compiled for ARM Cortex M4 (Atmel SAM4S16C) using ARM GCC v4.7.3. Recorder configuration Compiler optimization Flash usage Basic features -Os (minimum size) [...]

(This answer is only applicable for Percepio's own recorder library, used for e.g. FreeRTOS, OpenRTOS, SafeRTOS and Micrium µC/OS) Interrupt handlers (ISRs) are not recorded by default. To record ISRs, you need to add two calls in the interrupt handlers you wish to record, vTraceStoreISRBegin in the very beginning and vTraceStoreISREnd in the very end. [...]

You need to set a name for the ISR using vTraceSetISRProperties, otherwise the numeric ID stored using vTraceStoreISRBegin is displayed.

If you have interrupt handlers using interrupt-level kernel functions, but are not calling vTraceStoreISRBegin and vTraceStoreISREnd, the recorder assumes that the kernel call was made from an interrupt handler, but does not know the identity of the interrupt handler. In this case, the name is set to "ISR using Object", where Object is the queue [...]

Use vTraceSetQueueName, vTraceSetSemaphoreName or vTraceSetMutexName, as in the below example: actuatorQ = xQueueCreate(3, sizeof(QueueMessage) ); if (actuatorQ != NULL) { vTraceSetQueueName(actuatorQ, "ActuatorQueue"); // Set the name ... } else { ... // Error handling }