Ada Programming/Attributes/'Address

Computing » Computer Science » Computer Programming » Ada Programming

---

Attribute Definition Clause

X'Address is an Ada attribute where X is any object, program unit, or label, RM 13.3(10/1). [A program unit is either a package, a task unit, a protected unit, a protected entry, a generic unit, or an explicitly declared subprogram other than an enumeration literal, RM 10.1(1).]

'Address may be used to return the address of the first element allocated to X. 'Address may also be used to set the address of X for stand-alone objects and program units, RM 13.3(12).

-- A 32 bit hardware register
Device_Input_Value: Interfaces.Unsigned_32;
for Device_Input_Value'Address use System.Storage_Elements.To_Address (16#8000_05C4#);

It's not recommended to use Integer_32 in this case.

Aspect Specification

The address may also be specified directly when declaring the variable using an aspect declaration:

Device_Input_Value : Interfaces.Unsigned_32 with Address => System.Storage_Elements.To_Address (16#8000_05C4#);

See also

Wikibook

• Ada Programming
• Ada Programming/Attributes
• Ada Programming/Attributes/'Alignment

Ada Reference Manual

• 13.3 Operational and Representation Attributes (Annotated)
• Annex K Language-Defined Attributes (Annotated)