Quality RTOS & Embedded Software

 Real time embedded FreeRTOS RSS feed 
Quick Start Supported MCUs PDF Books Trace Tools Ecosystem TCP & FAT Training




Co-routines
[More about co-routines...]

Co-Routine States

Co-routines are only intended for use on very small processors that have severe RAM constraints, and would not normally be used on 32-bit microcontrollers.

A co-routine can exist in one of the following states:

  • Running

    When a co-routine is actually executing it is said to be in the Running state. It is currently utilising the processor.

  • Ready

    Ready co-routines are those that are able to execute (they are not blocked) but are not currently executing. A co-routine may be in the Ready state because:

    1. Another co-routine of equal or higher priority is already in the Running state, or
    2. A task is in the Running state - this can only be the case if the application uses both tasks and co-routines.

  • Blocked

    A co-routine is said to be in the Blocked state if it is currently waiting for either a temporal or external event. For example, if a co-routine calls crDELAY() it will block (be placed into the Blocked state) until the delay period has expired - a temporal event. Blocked co-routines are not available for scheduling.

There is currently no co-routine equivalent to a tasks Suspended state.

Valid co-routine state transitions






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




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

Latest News

FreeRTOS kernel V10 is available for immediate download. Now MIT licensed.


FreeRTOS Partners

ARM Connected RTOS partner for all ARM microcontroller cores

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