IODef Function

Returns whether the specified input or output bit, byte, word, or I/O label are defined.

Syntax
IODef (IOType, IOWidth, portNumber)

IODef (IOlabel)

Parameters

IOType

Integer value representing the type of I/O

• 0 - Input
• 1 - Output
• 2 - Memory

IOWidth

Integer value for port width: 1 (bit), 8 (byte), or 16 (word)

portNumber

Integer value representing the bit, byte, or word for which the label is to be returned

IOlabel

String expression that specifies standard I/O or memory I/O label in a string.

Return Values
True if the specified input or output bit, byte, word or the I/O label are defined, otherwise False.

See Also
IOLabel$, IONumber

IODef Function Example

Integer i

     For i = 0 To 15
       If IODef( 0, 1, i) = TRUE Then
         Print "Port " , i, " is defined"
       Else
         Print "Port " , i, " is undefined"
       EndIf
     Next i