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




Loading

Tickless FreeRTOS on an EFM32 Giant Gecko, serial issue after wakeup from EM2

Posted by petewaddy on February 10, 2015

I have code running on custom hardware using a EFM32GG arm device, and while attempting to use tickless , coupled with EM2 to achieve max current saving I've come across a problem when returning from EM2 sleep.

As part of the main loop a simple on/off led toggling with delay is used, a running counter is incremented and output via serial port running at 57600. After return from EM2 the first two or three bytes of the serial message are corrupt, but following bytes are correct.

The code for EM2 does a restore to the main HF clock which in this case is a 16MHz external XTAL.

It still looks like it could be a clock speed issue, any thoughts?


Tickless FreeRTOS on an EFM32 Giant Gecko, serial issue after wakeup from EM2

Posted by davedoors on February 10, 2015

The EFM parts wake from sleep very quickly by temporarily running on a slower clock instead of waiting for the PLL to lock. Sounds like that could be your issue.


[ 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