I'm currently using LPC2214 and FreeRTOS v5.3.0.

There are 6 tasks in my project.
Led flashing task - priority 0
Com 0 task - priority 2
Com 1 task - priority 2
Data Collect task - priority 1
Data Process task - priority 3
Error Check and Watch dog feed task - priority 4

Com 0 task is just some delay and output the keyboard input to the screen. Com 1 task does the communication, it checks the data received by the serial port and post it to data process task through a queue.Data process task with the second highest priority will do some data processing works.Then the com1 task should return the packet. Data collect task collect data in the back ground.
Error check task feeds the watch dog within the limit time.

The phenomenon is that the serial communication fails once 5 hours(the communication is 1 second a time). And the host device will report that the slave is "down".

I first cut the com 0 task, then I shorten the watch dog feed time, but neither works. And now I seems to get lost.

Regards.
wFrancis

I further checked the case. And found I have moved the interrupt vector into the start point of ram.May be this causes some unstability.Now I am still testing it, with the vector in rom mode.

Btw, can anyone show me a way to enable vectors in ram in a safe and right way.

Thanks.
wFrancis