I am using FreeRTOS+TCP from FreeRTOS Lab Version 160919 on the Zedboard with a ZYNQ SOC. I have 2 Tasks running. The first task has the highest priority and calls a calculation function periodically using vTaskDelayUntil(). The tick rate is 10000Hz and the calculation function is called every 10 microseconds. The second task just idles in a forever loop doing nothing and has low priority.
I get a jitter of the second function call in the range of 30ns.
Now to my problem: When I activate the IP stack using FreeRTOS_IPInit I get a jitter which is way higher than before and in the range of 7µs.
The task priorities are: Task1: 5, Task2: 1, IP-Task: 2, Tmr Svc:6
Can you explain this behaviour? Is there any way to reduce the jitter introduced by the IP-Task?
Thank you for your help.