Quality RTOS & Embedded Software

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



Posted by Richard on April 10, 2005
Nowadays I study FreeRtos operating system,but I can't understand "kernel tick" issue. what is a tick? I downloaded a ebook which is called "Real-Time Concepts for Embedded Systems" but I couldn't find anything about "ticks". Please explain me that concept.

RE: Ticks?

Posted by Richard on April 10, 2005
[This was an email support request which I have copied to this forum.]

The RTOS tick is a fixed interval periodic interrupt generated form a hardware timer. It is used to measure ‘real time’. The resolution of time that can be measured is dependent on the ‘tick period’.

For example, if the RTOS ‘tick frequency’ is set to 1ms then time can be measured with an accuracy of 1ms – but there is also an overhead of having an interrupt every 1ms. If this resolution is not necessary (it usually isn’t) then the overhead can be reduced by slowing down the tick frequency to say 10 or even 100ms.

The tick interrupt is also used for round robin scheduling. When there is more than one task that have the same priority and are ready to run, then the tick interrupt is used to switch between the tasks.

[ 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