How to make a serial to parallel conversion in simulink?

Please help: If there is an integer number source with : M-ary = 2 and Sampling time Ts = 1e-3 (1 ms). I want to make a serial to parallel simulink model with the following describtion:

                                         Output sequence (1)
    Input bits sequence:                    1 2     7 8 
1 2 3 4 5 6 7 8 9 10 11 12                                               as shown in figure.
                                         Output sequence (2)  
                                          3 4 5 6   9 10 11 12

- With the following conditions: The total sample time of bits (1 2) is 4 ms and total sample time of bits (3 4 5 6 ) is 4 ms too. and the are out in the same time.

[Amee Badiani]

I need help to solve the same thing... Kindly help.!