After some discussions this afternoon with TD support and get a good advice from them, this post details some notice about TD_USER_Loop working way and power saving.
For those like experienced with Arduino, Telecom Design loop is not working like
while(1) { loop(); }
But it is called on Interrupt ; I don’t know why but I was expecting it to be called every tick (32KHz) which was a wrong assumption. In fact, this procedure is called on wake up from any interrupt. The frequency of call can’t be determined, it can be not called in a minute if no events occurs. That is why schedulers helps you to have a predictable call.