Here's some thoughts on this subject from a VERY competent friend with great
experience in both HLLs & assembler.


        Russell McMahon

_______________________________________

To: "Russell McMahon" <apptech@paradise.net.nz>
Sent: Sunday, April 21, 2002 11:41 AM
Subject: RE: [PIC]: Assembler versus High level languages <-- Re: [PIC]:c
interrupts


> HLL's and assembler are simply tools to achieve an end and each has its
> place.
>
> I liken them to the difference between a handsaw and power-saw saw.  One
is
> ideal for doing a lot of general work with great efficiency.  The other is
> essential for fine finishing and high craftsmanship.  Sometimes you need
to
> use both to do a job properly.  So much for the Zen of programming.
>
> I use both extensively, however when you need to get a lot of
functionality
> into the smallest possible code space in an embedded  microcontroller (and
> have the time to do it), HLL's cannot compete with working in assembler
> (although thay can still be great for prototyping code).  We routinely
deal
> with what are widely regarded as the best optimising compilers for several
> 8-bit and 16-bit microcontroller families and (despite what their vendors
> say), they cannot even come close to the compactness of code we can
achieve
> in assembler on a good day.
>
> In one case in point, we re-coded the code for a mature medium-volume
> domestic appliance originally (competently) written in C, in hand-crafted
> assembler.  We reduced the code size to 43% of the original size (and
added
> some new features and functionality along the way including in-built
support
> for factory testing).  It took about 19 weeks.  It allowed the
manufacturer
> of the appliance to drop down two memory sizes (from a 32k-byte 8051
variant
> to an 8k variant), and saved them around US$1.30 per unit.  On the basis
of
> their production volumes, our efforts will repay their investment in a
> couple of months (less time than it took us to do it).
>
> It was right that the code should have originally been written in C.  That
> minimised the original development time and allowed changes to be made
> readily as the product evolved and matured.  Once the product design was
> stable and production volumes were up, it made sense to use assembler.
>
> It all depends on the nature of the application   - there is no one rule.
>
> Regards,
>
>     Ken Mardle

--
http://www.piclist.com#nomail Going offline? Don't AutoReply us!
email listserv@mitvma.mit.edu with SET PICList DIGEST in the body