Design Requirements Design a digital system with the following functionality. As shown, the data inputs (A \& B) and output (R) are 4-bits width busses, while Co is only 1-bit width. The M is the control input, which sets the operation of the circuit as indicated in the following table, where M is a bus of width =2. Note:- The (+) represents the arithmetic plus (add) operation. Design Approach In Logisim, the design should have three levels - Level-1:- A sub-circuit integrating the complete 4-bit adder. Build the 4-bit adder using 1-bit Full Adder. - Level-2:- A sub-circuit integrating the 4-bit adder sub-circuit and any other required components to complete the circuit. Use any component; e.g. MUX, Decoder, logic gates, etc. - Top-level:- The main working area, only one block with i/o. Documentation 1. A list of all the modules used in the design. Use the following table. Put the number of rows depending based on your design. If you are using discrete logic gates, include them too. 2. A clear image of the sub-circuits Do not forget to add a title as well as your name(s) on the design area (using the Text Tool). 3. Put different images of the top-level (main) circuit showing different states; i.e. M=00,01,10, and 11. For each case, add a label with a brief description. 4. Estimate the cost of your design based on the following - Each gate costs 0.1 unit - Each component (unit/module) costs 1 unit. - Do not include the I/O pins or any wiring component, e.g. the splitter