7. Hierarchical Design allows the partitioning of a system into manageable modules or components. Hierarchical Design reduces the complexity required to represent the schematic diagram of a circuit. A module is a functional block with specified interfaces. Then, the modules are combined or connected with other modules to describe the circuit or system. Once a module works can use as a building block. The modules can be reused. This reduces design time and design errors. Also, each module or sub-system can be designed and tested individually.
8. A full-adder is a combinational logic circuit that adds three bits and generates a sum bit and a carry-out bit. The full-adder has the three input bits A, B, and carry-in, CI and the two output bits sum and carry-out, CO. The Ripple Carry Adder is constructed by daisy chaining full-adder blocks in series. The carry-out of one stage is input to the carry-in of the next stage. An n-bit Ripple Carry adder, it requires n full adders. The daisy chaining technique combines smaller versions of devices to make larger versions.
9.…show more content… Propagation delay is the time required for a change in logic level to travel from the input to the output of a logic gate or a logic circuit. The transistor is a semiconductor device that can be used as an electronic switch and is the basic building block of an integrated circuit for logic gates. The propagation delay is due to the limitations in transistor switching speeds caused by undesirable internal capacitive stored charges. The electronics charges built up inside the digital circuit will not allow the circuit to change levels instantaneously. Propagation delay limits the switching speed or frequency of the logic circuit. If the propagation delay is small, then the operation of the logic circuit frequency is high. The propagation delay must be smaller than the minimum clock
