Channel in global memory

Can you be more specific because by the very definition of a channel it's a point to point connection and not a memory mapped resource. What you can do is read data from global memory and push it into a channel or pull data from a channel and write it to global memory. If that's not what you are asking about then we'll need more information, perhaps describe what you want to do and we can let you know the most straightforward way to achieve it.