Combinational logic circuits are circuits build using only combinational logic components. Combinational logic components are digital components which may or may not be clocked but does not have any storage element. Storage element are flip flops or can store past values.

Examples of combinational logic circuits are tr-state buffer, encoders/decoders, arithmetic components like adder, subtractor, multipliers, multiplexer and demultiplexers, shift operators, parity checkers.

Any digital system is made up of combinational logic components and sequential logic components. While combinational logic components are used in data processing and usually as datapath components, sequential components are used as control and sequencing components and memories devices such as registers or RAM/ROM.

Combinational logic components are thus building blocks types of digital system. These components can be bought as individual components as the 74 TTL or CMOS series. Or they can be implemented in FPGA chips. If individual components are bought then they are attached to printed circuit boards and connected via the copper traces. This may be both cumbersome and not economical because most often the components come in pairs such as two adders in a single chip whereas only one is required. Thus it can be wasteful of resources when buying or using individual components. The alternative is to use FPGA chips. Herein, the individual combinational component or circuit can be realized by writing FPGA program code.

The books digital system engineering pdf and digital systems design using vhdl 2nd edition pdf free download have examples and more explanation to this.


0 comments:

Post a Comment

 
Top