Quality RTOS & Embedded Software

 Real time embedded FreeRTOS RSS feed 
Quick Start Supported MCUs PDF Books Trace Tools Ecosystem


Missing Interrupts on M4

Posted by rdhammond15 on February 24, 2017

I am running FreeRTOS on an Infineon XMC4500F100K1024. Every once in a while the system tick ISR never gets exectued. During those periods, it seems like no interrupts excute. The only interrupts that are enabled are: Systick, PendSV, and DMA block transfer.

I've managed to set a breakpoint during one of these periods of lack of interrupts. Here are some register values: BASEPRI: 0 FAULTMASK: 0 ICSR: ISRPENDING: 1 PENDSTSET: 0 VECTPENDING: 0 VECTACTIVE: 0 SYST_CSR: ENABLE: 1 TICKINT: 1

I have the kernel priority set to 63 (it then properly gets shifted over by 2). The syscall priority is set to 5. Any idea as to what is happening to the interrupts would be greatly appreciated. I've attached a picture of a GPIO going high upon entering the systick ISR and then low on exiting. It also shows a GPIO going high when taskENTERCRITICAL is called and low when taskEXITCRITICAL is called. This is the only method to turn on/off interrupts. The missing ISRs usually have a period of ~100ms.

Missing Interrupts on M4

Posted by rdhammond15 on February 24, 2017


Capture.PNG (8732 bytes)

Missing Interrupts on M4

Posted by rdhammond15 on February 24, 2017

Solved the issue. A stack that I integrated was calling gettimeofday. This caused the undefined behaviour I was seeing.


Capture.PNG (8732 bytes)

[ Back to the top ]    [ About FreeRTOS ]    [ Privacy ]    [ Sitemap ]    [ ]

Copyright (C) Amazon Web Services, Inc. or its affiliates. All rights reserved.

Latest News

NXP tweet showing LPC5500 (ARMv8-M Cortex-M33) running FreeRTOS.

Version 10.1.1 of the FreeRTOS kernel is available for immediate download. MIT licensed.

View a recording of the "OTA Update Security and Reliability" webinar, presented by TI and AWS.


FreeRTOS and other embedded software careers at AWS.

FreeRTOS Partners

ARM Connected RTOS partner for all ARM microcontroller cores

Espressif ESP32

IAR Partner

Microchip Premier RTOS Partner

RTOS partner of NXP for all NXP ARM microcontrollers


STMicro RTOS partner supporting ARM7, ARM Cortex-M3, ARM Cortex-M4 and ARM Cortex-M0

Texas Instruments MCU Developer Network RTOS partner for ARM and MSP430 microcontrollers

OpenRTOS and SafeRTOS

Xilinx Microblaze and Zynq partner