Quality RTOS & Embedded Software

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


Loading

xQueueGenericSend on AVR

Posted by Geza Balazs on December 8, 2009
Hi,
xQueueGenericSend seems to take several hundreds of ticks to execute with interrupts disabled on AVR. This may be excessive in some cases in my application because my input capture IRQ can be delayed by even 1200-1300 cycles.
Is there some way to decrease this latency?
Thanks,
Geza

RE: xQueueGenericSend on AVR

Posted by Dave on December 8, 2009
Two ways to make sure its fast...

i/ Make sure the system is in a state where the task calling xQueueGenericSend() does not go round any loops inside the function.

ii/ Make sure the task calling xQueueGenericSend() does not get put into the blocked state within the function (because sending to the queue unblocks another task).

RE: xQueueGenericSend on AVR

Posted by Geza Balazs on December 8, 2009
Ok, thanks!
However, I don't fully understand (i). I've checked the code, it has a for(;;) statement at the beginning, but it's not wrapped by a critical section, so some time still in the loop interrupts will be re-enabled, right? So how does it impact my case?


[ 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.

Meet Richard Barry and learn about running FreeRTOS on RISC-V at FOSDEM 2019

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.


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

RTOS partner of NXP for all NXP ARM microcontrollers

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