Re: Ada and Automotive Industry

[Ken Garlington <garlingtonke@lmtas.lmco.com>]

granville@decus.org.nz wrote:
> 
>  We studied implementing Ada, for the C51 ( and still do so ), but have
> decided not to proceed. It may be possible, but it is not practical,
> nor efficent.
> 
>  We need a language that can run comfortably on the tiny FLASH C51's with
> 1K of CODE and 64 bytes of RAM, as well as the more common 8-16K cores,
> and even > 64K bankswitched cores.
> 
>  With the opening of Ada, and the talk of 'legal subsets', it would certainly
> be possible to do a Modula-2 subset of Ada on the C51, but you would have
> very poor portability as all vendors would do different 'subsets'.

Actually, there are now mechanisms in place that could help with portability. 
Assuming someone wrote a specification of a language subset, and defined it in
terms of pragma Restrictions, it might be possible to get a group like ACM
SIGAda, the ARA, etc. to promote it as an informal standard, and possibly get
it included as an annex in a future revision of the standard. This approach
is being used right now to promote standard bindings for Ada.

>  Remember that Heap, Pointer, and dynamic memory work is not a C51 strongpoint.
> Fast interrupts, and boolean control logic is.

Fortunately, Ada 95 supports both fast interrupts (e.g., using procedures as
interrupt handlers) and boolean control logic. It also provides generics and
strong typing, which can be used with minimal overhead with most compilers.
I've implemented Ada programs on several systems with no use of the heap, so
it should be doable for a C51 (assuming the selection of an appropriate subset
of the language).


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