Quality RTOS & Embedded Software

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


limits on simulation

Posted by tns1 on October 3, 2008
I have been trying to simulate some of the FreeRTOS ARM demos, but I see now that any task switching dependent on the timer tick is not going to work unless the timer and irq are also simulated.
I was confused for a bit because it looked like I was getting some task switching, or task switching for a while anyway. This was under the GNUARM GCC/Insight, and the Rowley simulators.

For instance, taking the LPC2368 demo for Rowley, I would load the demo code and place breakpoints both in main, and in each task. I can hit breakpoints inside those tasks about 10-20 times and then the debugger does not find any more. Rowley says they do not simulate the timer, so how to explain what I am seeing?

With no timer, I wouldn't expect to hit any breakpoints in tasks, except maybe just the 1st one, or maybe if taskYIELD was being used.

Are there any ARM simulators which can handle the task switching?

RE: limits on simulation

Posted by Richard on October 3, 2008
There have been posts regarding SkyEye and Qemu here before. I think both are possible. The other alternative is to try the Keil simulator. Most other IDEs will only simulate the core, not the peripherals.


RE: limits on simulation

Posted by tns1 on October 3, 2008
The many calls to taskYIELD in the code, explain why the '2368 demo appeared to be working initially under the Rowley simulator despite having no timer tick. A good sanity check is to put a watch on xTickCount. I can see for the Keil simulator, that the value does change.

[ 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