With Softdevice enabled, the freertos queue receive, once in a while takes around 300 us

[induja]

Hello,

I am using

nordic nrf52 SDK version : v15.2.0

Freertos version : V10.0.1

The system has hardware timer which runs at 6.4KHz. For every 1.6 KHz, from timercallback, there is one value sent to task using "xQueueSendFromISR". The task receive the value from the queue.

With soft device enabled, sometimes the task receives from the queue after 300 us(microseconds)  which is an overhead as in our system as we perform certain time critical operations.

However without soft device , it takes 40 us and worst case of 80 us.

is there any way to fix the issue.?

[Vidar Berg]

Hi,

As you may know, the Softdevice reserved the highest interrupt priorities to handle timing-critical protocol events, see Processor usage patterns and availability. So application tasks will get blocked from time to time. Would it be possible to execute this timing in the ISR context, and possibly with a higher interrupt priority to mitigate this?  

Best regards,

Vidar