
15.14 Digital Systems: Principles and Design
15.5 DATA TYPES
Consider a data object.
1. Each data object can have a value which is from a set of values.
2. Each data type defines a set of values.
3. Each data type also defines a set of permitted operations.
A type is declared for a data object using type declaration. For example,
consider declaration of type for a valid tele_digit permitted for dialing.
type tele_digit is (‘0’, ‘1’, ‘2’, ‘3’, ‘4’, ‘5’, ‘6’, ‘7’, ‘8’, ‘9’); -- An enumerated
data type which can discrete values among ten values.
There are four types of data as given in Table 15.3.
There are four scalar types of data as given in Table ...