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Default values in VHDL
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Default Values


The one remaining part of a procedure parameter list that we have yet to discuss is the optional default value expression, shown in the syntax rule on page 61.  Note that we can only specify a default value for a formal parameter of mode in, and the pa- rameter must be of the class constant or variable.   If we include a default value in a parameter specification, we have the option of omitting an actual value when the pro- cedure is called.  We can either use the keyword open in place of an actual parameter value or, if the actual value would be at the end of the parameter list, simply leave it out.   If we omit an actual value, the default value is used instead.




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