The AVR Context
[RTOS Implementation Building Blocks]

A context switch requires the entire execution context to be saved. On the AVR microcontroller the context consists of:
  • 32 general purpose processor registers. The gcc development tools assume register R1 is set to zero.
  • Status register. The value of the status register affects instruction execution, and must be be preserved across context switches.
  • Program counter. Upon resumption, a task must continue execution from the instruction that was about to be executed immediately prior to its suspension.
  • The two stack pointer registers.

    AVRContext.gif


Next: RTOS Implementation – Saving The Context


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

Latest News

FreeRTOS v10.2.1 is available for immediate download. MIT licensed, includes 64-bit RISC-V, NXP Cortex-M33 demo & Nuvoton Cortex-M23 demo & STM32H745 dual core (AMP) demo.

New Updates to MIT licensed IoT MQTT and POSIX libraries are now available. New library IoT HTTPS is available.  Includes demo projects.

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

Careers

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
Renesas
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