Quality RTOS & Embedded Software

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


[AVR] portYIELD_FROM_ISR should be provided

Posted by BeginEnd on April 18, 2013
I think that there should be macro portYIELD_FROM_ISR and function vPortYieldFromISR() added to ATMega323 port.
This is becouse vPortYield() uses "ret" to return, but if current contex was switched in vPortTickFromISR(), restored SREG do not have global interrupt flag set.

RE: [AVR] portYIELD_FROM_ISR should be provided

Posted by Richard on April 18, 2013
This (extremely old) port is explained in on the following (extremely old) web pages. I have only linked to the two relevant pages:


SREG is saved and restored as part of the task context. When a task that is switched out from an interrupt is next executed it will be switched back into the interrupt (from exactly where it was switched out) - where it will execute its end of interrupt code setting SREG back to its required value. Likewise if a task is switched in from inside an interrupt it will start executing from wherever it was switched out - which may or may not be in an interrupt but its SREG will also be correct for wherever it ends up.


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

Copyright (C) 2004-2010 Richard Barry. Copyright (C) 2010-2016 Real Time Engineers Ltd.
Any and all data, files, source code, html content and documentation included in the FreeRTOSTM distribution or available on this site are the exclusive property of Real Time Engineers Ltd.. See the files license.txt (included in the distribution) and this copyright notice for more information. FreeRTOSTM and FreeRTOS.orgTM are trade marks of Real Time Engineers Ltd.

Latest News:

FreeRTOS V9.0.0 is now available for download.

Free TCP/IP and file system demos for the RTOS

Sponsored Links

⇓ Now With No Code Size Limit! ⇓
⇑ Free Download Without Registering ⇑

FreeRTOS Partners

ARM Connected RTOS partner for all ARM microcontroller cores

Renesas Electronics Gold Alliance RTOS Partner.jpg

Microchip Premier RTOS Partner

RTOS partner of NXP for all NXP ARM microcontrollers

Atmel RTOS partner supporting ARM Cortex-M3 and AVR32 microcontrollers

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

Xilinx Microblaze and Zynq partner

Silicon Labs low power RTOS partner

Altera RTOS partner for Nios II and Cortex-A9 SoC

Freescale Alliance RTOS Member supporting ARM and ColdFire microcontrollers

Infineon ARM Cortex-M microcontrollers

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

Cypress RTOS partner supporting ARM Cortex-M3

Fujitsu RTOS partner supporting ARM Cortex-M3 and FM3

Microsemi (previously Actel) RTOS partner supporting ARM Cortex-M3

Atollic Partner

IAR Partner

Keil ARM Partner

Embedded Artists