Monday, January 7, 2008

Block diagram: A ‘lazy(?)’ way to study

Since these few days I sketched quite a lot of block diagram for my project (Some of it goes to the dustbin .... ) , I think it is good to write something about block-diagramming.
A picture tells thousands words
so do block diagram (err... maybe not a thousand, but just enough to get an idea of something)

Before spending time reading lengthy explanation of software/hardware architecture, consider looking at the block diagram first. The lengthy paragraph actually further explaining the block diagram.

Given below is some information I think will help in understanding some architecture:

  • Block usually in square represent components or modules
  • Block(s) within a block represent the sub-modules or “the component consists of ….. components”
  • Usually the blocks are connected with connector. The connector can be categorized as:
    • Bidirectional : Interdependent / data can flow in both direction
    • Unidirectional : one block depends on another block / data flows from one direction to another direction
    • Thick connector : represent large data / bigger relationship
    • Single line connector : represent less data
  • There are labels most of the times are in short form. Labels represent what is the block and most of the time hints its function. Example (relevant for Microcontroller or Microprocessor subjects ):
    • CPU (Central Processing Unit) is a unit that is central (most/every component should connect to it), it process something (in this case program and data)
    • ALU (Arithmetic Logic Unit) is a unit that does something (logically operation/calculation) arithmetically or logically. The basic arithmetic is addition, subtractions, division and multiplication. The basic logic is AND, OR, NOT, XOR ………….
    • Memory is to memorize something (obviously data/program)
  • The functions of each block are specific. Memory does not process it just stores, while CPU specific for processing not for storage
  • Keep in mind that designer also use block diagram in the thinking process to build the system/architecture.

Precaution: This tips helps, but I believe that to gain marks in exam, students are required to write the definition as in the text book / given by the lecturers.

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