Send Message From ISR -port LPC2212

Hello, I’m trying to make a serial driver. Therefore I have to send a message from an ISR. This message sometimes awake a different task from the one it is interrupting, and sometimes the same task that was interrupted. Referring to the documentation I have to use taskYIELD_FROM_ISR () when the task has been awaken. But It is apparently not defined  in the code. How can I do then. I tried without it but I can merely send an receive characters once. And I tried with taskYIELD and portYIELD_FROM_ISR() which does not work at all What should I do and where is this  taskYIELD_FROM_ISR () defined?

Send Message From ISR -port LPC2212

There is inconsistency in the naming of this macro. Depending on the compiler you are using it might be called portEND_SWTICHING_ISR. Look at the example interrupt service routines that came with the port you are using to see how it is done.