3. Data Types

• Values can be encoded in a computer as bit patterns.

• Operations on values recognize data types, in conjunction with the encoded information.

• This means that ISA^(*) operations are constrained to operate only on particular data types.

• A data type presumes knowledge about data size, set of operations, and internal order of encoding of the actual 1s and 0s.

• For example,

  • positive and negative integers

  • floating point numbers, such as 3.14

  • ASCII codes that represent printable characters

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  ^(*) ISA stands for Instruction Set Architecture.