CC2652R7: TI RTOS task priority

Jermyn Lau

Part Number: CC2652R7

Tool/software:

Hi Team,

I am developing a firmware using CC2652R7 TI RTOS based on a simple peripheral example. I am confused about the priority of tasks.

For my understanding, the higher task priority numerical value, the higher order of the task, right? But I cannot find a reference that clearly clarify it. May I know is there any reference to clarify this? Thanks a lot.

Best,

Jermyn

1 month ago

0 Alex Fager 1 month ago

TI__Genius 12391 points

Hello Jermyn,

Our BLE expert should be able to help you shortly!

Thanks,
Alex F

0 Jan 1 month ago

TI__Mastermind 42100 points

Hi Jermyn,

If I am not mistaken, the higher the numerical value, the lower the task priority. So a task with priority 4 would be lower priority than one with priority 3. Are you seeing something different on your side?

Best Regards,

Jan

0 Jermyn Lau 1 month ago in reply to Jan

Prodigy 90 points

Hi Jan,

Can you show me some references? It really confused me, from TI official document (TI-RTOS Overview — TI 15.4-Stack 0 documentation), it only mentioned this, but do not specify the relation of the numerical value and priority order:

Numeric priorities are assigned to tasks, and multiple tasks can have the same priority. Tasks are readied to execute by highest to lowest priority level; tasks of the same priority are scheduled in order of arrival. The priority of the currently running task is never lower than the priority of any ready task. The running task is preempted and rescheduled to execute when there is a ready task of higher priority.

However, from an older post (sys bios task priority meaning - Processors forum - Processors - TI E2E support forums), Alan answered:

Unless you are explicitly setting Task.numPriorities = 32, the default range of usable task priorities are 1 thru 15.
Priority 0 is reserved for the Idle Task.
For SYS/BIOS, task priority 1 is lower than task priority 15.

Also from this post(https://e2echina.ti.com/support/wireless-connectivity/sub-1-ghz/f/sub-1-ghz-forum/175718/ti_rtos), Alvin answered the higher value, the higher priority order.

Could you help to clarify this? Thank you so much,

Best,

Jermyn

0 Jan 1 month ago in reply to Jermyn Lau

TI__Mastermind 42100 points

Hi Jermyn,

My apologies, you are correct. I mixed up the priority ordering between TI-RTOS and FreeRTOS.

Best Regards,

Jan

0 Jermyn Lau 1 month ago in reply to Jan

Prodigy 90 points

Hi Jan,

1) Thank you, may I know is there official TI document can clarify that?

2) Besides, from this website about FreeRTOS (Tasks - FreeRTOS), it mentioned Low priority numbers denote low priority tasks. The idle task has priority zero (tskIDLE_PRIORITY). So the priority ordering should be the same between TI-RTOS and FreeRTOS?

Because this order is critical for my firmware structure, I need to clarify it. Thanks a lot.

Best Regards,

Jermyn

0 Jan 1 month ago in reply to Jermyn Lau

TI__Mastermind 42100 points

Hi Jermyn,

I took a look through the TIRTOS Users' Guide and found the following section that mentions the ordering:

The link to the user's guide may be found here: https://dev.ti.com/tirex/content/simplelink_cc13xx_cc26xx_sdk_8_30_01_01/docs/tirtos7/Bios_User_Guide.pdf

My apologies for the confusion.

Best Regards,

Jan

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CC2652R7: TI RTOS task priority