INSERT OPERATION
The insert operation inserts a new value into a set of bits. This is done by first masking bits and then O ring them with required value. For illustration, suppose that an A register have eight bits, 0110 1010 to replace the four leftmost bits by value 1001 we first four unwanted bits:-
0110 1010 A before
0000 1111 B (mask)
0000 1010 A after masking
And then insert new value:-
0000 1010 A before
1001 0000 B (insert)
1001 1010 A after insertion
mask operation is an AND microoperation and insert operation is an OR microoperation.