Block Diagram

Create block diagrams quickly and easily with SmartDraw's block diagram software

CPU Input Unit Output Unit Arithmetic & Logic Unit (ALU) Control Unit (CU) Memory Unit (MU)

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What is a Block Diagram?

A block diagram is a specialized, high-level flowchart used in engineering. It is used to design new systems or to describe and improve existing ones. Its structure provides a high-level overview of major system components, key process participants, and important working relationships.

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block diagram example
Scoreboard block diagram

Types and Uses of Block Diagrams

A block diagram provides a quick, high-level view of a system to rapidly identify points of interest or trouble spots. Because of its high-level perspective, it may not offer the level of detail required for more comprehensive planning or implementation. A block diagram will not show every wire and switch in detail, that's the job of a circuit diagram.

A block diagram is especially focused on the input and output of a system. It cares less about what happens getting from input to output. This principle is referred to as black box in engineering. Either the parts that get us from input to output are not known or they are not important.

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How to Make a Block Diagram

Block diagrams are made similar to flowcharts. You will want to create blocks, often represented by rectangular shapes, that represent important points of interest in the system from input to output. Lines connecting the blocks will show the relationship between these components.

In SmartDraw, you'll want to start with a block diagram template that already has the relevant library of block diagram shapes docked. Adding, moving, and deleting shapes is easy in just a few key strokes or drag-and-drop. SmartDraw's block diagram tool will help build your diagram automatically.

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manual block diagram
block diagram symbols

Symbols Used in Block Diagrams

Block diagrams use very basic geometric shapes: boxes and circles. The principal parts and functions are represented by blocks connected by straight and segmented lines illustrating relationships.

When block diagrams are used in electrical engineering, the arrows connecting components represent the direction of signal flow through the system.

Whatever any specific block represents should be written on the inside of that block.

A block diagram can also be drawn in increasing detail if analysis requires it. Feel free to add as little or as much detail as you want using more specific electrical schematic symbols.

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Block Diagram: Best Practices

  • Identify the system. Determine the system to be illustrated. Define components, inputs, and outputs.
  • Create and label the diagram. Add a symbol for each component of the system, connecting them with arrows to indicate flow. Also, label each block so that it is easily identified.
  • Indicate input and output. Label the input that activates a block, and label that output that ends the block.
  • Verify accuracy. Consult with all stakeholders to verify accuracy.
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simple block diagram

Block Diagram Examples

The best way to understand block diagrams is to look at some examples of block diagrams.

Click on any of these block diagrams included in SmartDraw and edit them:

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