From mboxrd@z Thu Jan  1 00:00:00 1970
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From: Stephen Leake <Stephen.Leake@gsfc.nasa.gov>
Subject: Re: System.Address_to_Access_Conversions
Date: 1998/07/13
Message-ID: <ud8b9a9xx.fsf@gsfc.nasa.gov>#1/1
X-Deja-AN: 371049584
References: <6odddl$k94$1@nnrp1.dejanews.com>
Organization: NASA Goddard Space Flight Center -- Greenbelt, Maryland USA
Newsgroups: comp.lang.ada
Date: 1998-07-13T00:00:00+00:00
List-Id: <comp.lang.ada>

jsanchor@my-dejanews.com writes:

> <snip>
> 
> I tried casting
> Ptr_to_Data := Ptr_to_Data_Type(Data_Ptr); --It compiled..but when I ran it
> SEGMENTATION FAULT ERROR showed up.
> Can anybody suggest how do I get the correct access type to point to memory.

You have the correct Ada syntax (that's why it compiled), but the
Operating System is not letting you write to that address (that's what
SEGMENTAION FAULT means).

The cure depends on what OS you are using. Most will NOT let you write
directly to arbitrary addresses (I assume this is a hardware device
register?) from user code. You will need to write a piece of code that
runs in kernel mode (normally called a "device driver").

If you give us more details about what's at that memory location, what
OS and CPU you are using, we might be able to help.
> 
> Thank you in advance.
> Jay S.
>
 You're welcome

-- Stephe