Hi, i want to know that, how to check minimal stack size requirement for task? because sometimes my task get stack because of Stack size requirement. How to calculate the minimal stack size reuirement?

That depends on the toolchain you are using. I’m using a static stack analysis tool for GNU: http://mcuoneclipse.com/2015/08/21/gnu-static-stack-usage-analysis/

Please see the FAQ on the topic: http://www.freertos.org/FAQMem.html#StackSize – to which I have just added a link to Erich’s blog.