Micrium OS Internal tasks#

Table - Micrium OS Internal tasks in the Appendix A - Internal Tasks page lists all the internal tasks automatically created by the Micrium OS along with their default priority. It is always possible to change the task priority after the module initialization.

Changing tasks priority must be done with care. Some tasks may have special requirements. Refer to the module's section of this user manual for more information.

Note that the default stack sizes have been deliberately set to a high value. It is recommended to configure them to a more appropriate size once your application is completed.

Table - Micrium OS Internal tasks#


Task	Module	Description	Default priority	Default stack size	Change priority with…	Change stack configuration with…	Default priority define
Timer	Kernel	Handles timer-based operations	5	256	OS_ConfigureTmrTask()	OS_ConfigureTmrTask()	KERNEL_TMR_TASK_PRIO_DFLT
Stat	Kernel	Maintain Kernel usage statistics	6	256	OS_ConfigureStatTask()	OS_ConfigureStatTask()	KERNEL_STAT_TASK_PRIO_DFLT
Service	CANopen	Handles CAN frames for different CANopen communication objects	9	512	CANopen_ConfigureSvcTaskStk()	CANopen_SvcTaskPrioSet()	CANOPEN_CORE_TASK_PRIO_DFLT
Hub	USB Host Core	Handles the USB Host Hub events	10	768	USBH_HUB_TaskPrioSet()	USBH_ConfigureHubTaskStk()	USBH_HUB_TASK_PRIO_DFLT
Scheduler	USB Host PBHCI	Handles Pipe-Based Host Controller Interface events	11	512	USBH_PBHCI_SchedTaskPrioSet()	USBH_PBHCI_ConfigureSchedTaskStk()	USBH_PBHCI_TASK_PRIO_DFLT
SD Core	IO-SD	Handles SD events (card connection, disconnection, interrupts) and data transfers	14	512	SD_CoreTaskPrioSet()	SD_ConfigureCoreTaskStk()	IO_SD_CORE_TASK_PRIO_DFLT
Net Core	Net Core	Handles timers and packet reception & deallocation	16	1024	Net_CoreTaskPrioSet()	Net_ConfigureCoreTaskStk()	NET_CORE_TASK_CFG_PRIO_DFLT
Net Core WiFi*	Net Core	Handles third party drivers that require it	17	-			NET_CORE_IF_WIFI_TASK_PRIO_DFLT
HTTP_Client	HTTP Client Application		18	768	HTTPc_TaskPrioSet()	HTTPc_ConfigureTaskStk()	HTTP_CLIENT_TASK_PRIO_DFLT
MQTT Client	MQTT Client Application		19	512	MQTTc_TaskPrioSet()	MQTTc_ConfigureTaskStk()	MQTT_CLIENT_TASK_PRIO_DFLT
IPerf	IPerf Application	Handles test runs	20	512	IPerf_TaskPrioSet()	Iperf_ConfigureTaskStk()	IPERF_TASK_PRIO_DFLT
Telnet Server	Telnet Session	Handles client's session	21	512	TELNETs_InstanceInit()	TELNETs_InstanceInit()	TELNET_SERVER_SESSION_TASK_CFG_STK_SIZE_ELEMENTS_DFLT
Telnet Server	Telnet Service	Handles new client request	22	256	TELNETs_InstanceInit()	TELNETs_InstanceInit()	TELNET_SERVER_TASK_CFG_STK_SIZE_ELEMENTS_DFLT
TFTP Server	TFTP Server	Handles TFTP requests	23	512	TFTPs_TaskPrioSet()	TFTPs_ConfigureTaskStk()	TFTP_SERVER_TASK_PRIO_DFLT
Asynchronous	USB Host Core	Handles asynchronous events	25	512	USBH_AsyncTaskPrioSet()	USBH_ConfigureAsyncTaskStk()	USBH_ASYNC_TASK_PRIO_DFLT
Asynchronous	IO-SD	Handles SD data transfers	26	512	SD_AsyncTaskPrioSet()	SD_ConfigureAsyncTaskStk()	IO_SD_ASYNC_TASK_PRIO_DFLT
Media Poll	File System Storage	Handles removable media status polling	27	512	FSStorage_PollTaskPrioSet()	FSStorage_ConfigureMediaPollTaskStk()	FS_MEDIA_POLL_TASK_PRIO_DFLT
Net Services	Net Core	Handles network services such as DHCP	28	512	Net_CoreSvcTaskPrioSet()	Net_ConfigureCoreSvcTaskStk()	NET_CORE_SVC_TASK_CFG_PRIO_DFLT
Timer	USB Device HID class	Handles timer-based HID events	29	512	USBD_HID_TmrTaskPrioSet()	USBD_HID_ConfigureTmrTaskStk()	USBD_HID_TMR_TASK_PRIO_DFLT

* The Net Core WiFi Interface task may be required by some WiFi driver implementations, as is the case with the Qualcomm QCA400x. When applicable, the driver will take care of setting the stack size, and will use the task priority mentioned above. Such task configuration can be overridden by the user application and passed to the NetIF_WiFi_Add() function.