It is important to the line in the code editing window in the exact location where you want to insert a code snippet to produce the shortcut menu with the Insert Snippet command.

right -click

Explanation:

It is important to right - click  the line in the code editing window in the exact location where you want to insert a code snippet to produce the shortcut menu with the Insert Snippet command.

answer; insolated i/o uses separate memory space,and on the other hand memory mapped i/o uses memory from the main