Re: Much 16 bit Ada useage?

[John McCabe <john@assen.demon.co.uk>]

Niklas Holsti <nholsti@icon.fi> wrote:
>John McCabe wrote:
>> 
>> Mike Silva <mjsilva@jps.net> wrote:
>> >Question from a non-Ada (but curious) type: is there much use of Ada
>> >in the 16 bit world?  My specific interest (today) is the Siemens
>> >C167, but I don't want to limit the question to that chip.  I'm
>> >asking because I've only run across references to 32 bit chips so
>> >far.  Thanks.
>> 
>> There is fairly significant use of Ada on projects using MIL-STD-1750A
>> 16-bit processors such as the GPS MA31750, PACE1750A etc. The European
>> Space Agency's Envisat program has the MA31750 listed as the 
>> recommended microprocessor, and Ada (from TLD :-( has been mandated
>> for it.

>Just a note that several other ESA satellites use the MA31750,
>including XMM (X-ray science), INTEGRAL (gamma-ray science), MetOp
>(operational meteorology), ROSETTA (probe to comet Wirtanen),
>and no doubt others as well.

Thank you for that. It is now over a year since I left the european space 
industry and I kind of lost touch with what was going on.

>However, it seems that the European production of the MA31750 will
>stop,

That is correct. In actual fact I thought it had already happened. GPS, 
manufacturers of the MA31750 were sold off to Mitel of the US in February 
this year, and I can't see them continuing with the MA31750. There was 
talk about GPS producing a space qualified ARM processor, but I don't 
know what happened to that.

>so new projects are likely to use the European and space
>qualified implementations of the SPARC (ERC-32) or the ADI 21020
>DSP. (A port of GNAT for the latter would be nice. Does it exist?)

I don't know if it exists, but Tartan were working on Ada for the SHARC 
(AD 21060) before being bought by TI, so I don't know what's happened to 
that.

I can still see a market for 16-bit processors in space applications, and 
I'm sure they'll be supported by Ada compiler - although maybe not Ada95. 
One of the last jobs I worked on used the MA31750 because of its low 
power consumption and size, the availability of Ada (83) compilers, and 
the fact that you didn't need a lot of support circuitry. 

The problem with ERC-32 is that it's a multi-chip affair which uses 
masses of power. With the 21020 it has a form of Harvard architecture 
with quite wide address and data busses so could end up using a lot of 
real estate.


-- 
Best Regards
John McCabe
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