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Re: 2500AD C compiler for 6502

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Sunplus is focused on selling high-volume consumer product chips,
nearly all masked ROM. They don't welcome other types of business,
probably because they think their support costs would be excessive. If
you're able to sell micros starting at less than a dime, you've really
got to watch all of your costs. When I last dealt with Sunplus, they
had no direct support in the US, but depended on the sales reps
instead. In many ways their business model is the exact opposite of
Microchip's.

Regarding their 6502-like products, one motivation for limiting access
to tools might be to head off reverse engineering of products based on
them. (None of the Furby that I heard of ever actually got into the
code itself.) I also think they're trying to motivate customers who
need C to design in their newer 16-bit chips which do have an ANSI
compiler supplied by Sunplus, derived from gcc I think, although none
of these chips get down to the same price point as their 8-bitters.

Jim McGinnis

Re: 2500AD C compiler for 6502

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Supplying and support your own SW tools would increase costs.  Relying on
3rd party SW vendors would reduce costs.  How is designing and supporting
your own SW tools going to decrease costs?

--
Grant Edwards                   grante             Yow!  Where's th' DAFFY
                                  at               DUCK EXHIBIT??
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Re: 2500AD C compiler for 6502


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The costs that I imagine Sunplus worries about would come from
requests for chip data, prototyping boards and general
hardware/software integration support. These requests would be
encouraged as tools and information about their chips became more
widely known. I think they and their reps believe they already know
every potential customer, and any new inquiries would almost certainly
be a waste of effort for them. Also. there's a increasing tendency for
design to follow manufacturing over to southern China, so
strategically it may not be wise to increase investment in supporting
developers elsewhere.

Re: 2500AD C compiler for 6502
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Because the workflow with these parts - and the vendor accountability
- is just not in the same league as what most cae'ers would expect. By
way of example as to just how different these parts are from
mainstream microcontrollers: There is no testing and no functional
guarantee. Typically they supply a 1% overage to cover defectives. So
your Happy Meal toy doesn't work, and you give it back to the McWorker
and he gives you a replacement.

Code for these parts is supported by libraries supplied by the chip
vendor, supporting CELP, MIDI playback, etc etc - various
functionality which the chip vendors keep very secret. They don't want
to outsource that functionality, and they want minimal in-house
development costs, so they use, by-and-large, in-house tools.

It is *normal practice* in this industry segment for parts to be
supported only by proprietary tools. In this day and age, a large
percentage of toy micros are either 6502s or 65C816s under the hood,
but that's virtually useless information.

Re: 2500AD C compiler for 6502

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Interesting.  I think I'll stay out of that segment of the industry.

--
Grant Edwards                   grante             Yow!  Where's th' DAFFY
                                  at               DUCK EXHIBIT??
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Re: 2500AD C compiler for 6502
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:) It can be fun to work in, but it hardly encourages best practices.
Because the functionality of a toy isn't often well-defined (the box
tells you generalities only), the rule of thumb is "make sure that it
does SOMETHING when the user plays with it - ANYTHING is better than
nothing". So for instance in a toy with some communication system
(e.g. IR remote control) you should make it respond - somehow - to
spurious codes - regardless of the actual play pattern.

There are scams just waiting to happen in that industry (I'm surprised
I never heard of one). The sale contract for these parts often says
explicitly that Company XYZ made these parts using the
customer-supplied object code and their normal production process, but
that they performed no testing or other Q/C feedback. I.e. they fed
your recipe into the oven, and out came dice, so they cut them and
packed them and here you are - take it or leave it, no money back.

So they could ship you a thousand of someone else's part instead of
your part, or chips with a 99% defect rate, and you'd have no real
recourse. In theory you could sue in China - good luck on that route!

Re: 2500AD C compiler for 6502

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Oh yeah... I forgot about that little detail. Thanks for reminding me...

Once the Sunplus parts pass your own functional test, are they as
reliable as any other maker's (given the same level of firmware design)?

I wonder if anyone really knows, since most Sunplus 8-bit parts wind up
in toys. Unlike the average 8-yr-old, the end user of this product will
notice if the part resets frequently or something worse...

Thanks,
Wallace


Re: 2500AD C compiler for 6502
Hello Wallace,

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In general, with a very small sample size... I'd say yes, Sunplus is
as reliable as Winbond, or EMC, or King Billion, or Realtek, or...
However, reliability is really not a design parameter for these parts
:) Note that the intended functionality of these uCs is to spend most
of their lives asleep, to respond briefly to an interrupt, and then to
re-snooze.

Maybe they miss every ten-thousandth interrupt, reliably. There's no
way of knowing, because the 3yo target user just bashes the button for
the 10,001th time and the toy works again.

Maybe the core will overheat and explode if run continuously in a
tight loop for 37 minutes at Vbatt=4.0V. There's no way of knowing,
because the 3yo target user can't keep the thing running at 100% duty
for that long.

Issues like ESD sensitivity, timing, boundary conditions of Rosc or
other clock input, you're just so completely on your own. Even when
the datasheet says something on one of these topics, it can be utter
fantasy and you'll never get a response from the manufacturer beyond
"Ah, yes, we know there is mispring in datasheet".

On most of these toy parts, you can't even do a power-on firmware
checksum (and looky here, memory reliability isn't characterized -
fancy that!).

If I was designing anything non-trivial, I would *not* want to use one
of these toy chips, no matter who the manufacturer. If nothing else,
you can be sure that the support structure for any non-speaking-toy
application is nonexistent. And God knows, it's hard enough to get
semi-acceptable support on the intended application set.

A couple of vendors - Elan is the only one that comes immediately to
mind - do support using some of their parts in "microcontrolling" type
non-toy applications. But that is still the road less traveled, IMHO.
I'd certainly never consider doing anything critical with one of those
parts derived from the toy line.

Re: 2500AD C compiler for 6502

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Hmm, that certainly gives me pause. I'm familiar with the poor
documentation and general lack of information. Unquantified ESD behavior
is a little scary.

I'll check with Spectrum Rep to see what other non-toy applications are
using Sunplus' low-end chips. (I know they have USB host controllers and
other more advanced parts, too.)

Thanks,
Wallace


Re: 2500AD C compiler for 6502

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By my book, that means what these guys produce is not actually a
(general-purpose) microprocessor or -controller, but rather a
special-purpose part which will be essentially useless to anybody but
the narrowly defined target audience, and IMHO not worthy of mention
in this newsgroup.

As police men on crime scene watch would put it: "Move on, everybody,
nothing to see here --- just move on".

--
Hans-Bernhard Broeker ( snipped-for-privacy@physik.rwth-aachen.de)
Even if all the snow were burnt, ashes would remain.

Re: 2500AD C compiler for 6502

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I don't know about that... I would think a 8-bit microcontroller that
costs less than a quarter--or even a dime--would be of interest to lots
of developers, even if you do have to use proprietary tools.

At any rate, I thank everyone who's contributed to this thread. I know
it helps me, and evidently there are at least two other Sunplus
developers out there.

- Wallace


Re: 2500AD C compiler for 6502
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TANSTAAFL. You gets what you pays for. Cheap price implies that
something was sacrificed; in this case, quality control and
standardization.

Re: 2500AD C compiler for 6502
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I agree. That is also pretty much exactly what they will tell you, if you ask
them.

Re: 2500AD C compiler for 6502
On 11 Nov 2003 10:13:47 -0800, snipped-for-privacy@larwe.com (Lewin A.R.W. Edwards)

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Most of these parts will be chip-on-board, and since wire bonding has
a relatively high failure rate, I'm not sure how effective it is to
test prior to bonding. My own experience is that Sunplus's parts did
not have an unusually high failure rate, although it specs are pretty
fuzzy so you need to be conservative in interpreting them


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There are some exceptions. My former employer, Voice Signal
Technologies, sold Sunplus speech recognition libraries independently
from Sunplus.

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You can use any 6502 tools -- and there were lot of them in the Apple
II days -- to develop for the 6502-like chips, albeit with some effort
to remap opcodes if needed. The 2500AD toolset is more or less the
standard for Sunplus, however. I think they are the only commercially
supported 6502 tools still out there, and support does help when
you're on a tight schedule. I haven't heard of any 65C816 clones - do
you know who makes those?

Re: 2500AD C compiler for 6502

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Winbond's more recent parts (the top-of-the-line BandDirector things) have
that core, or so they told us. Also, there is a video game ASIC from Sunplus
that contains an '816. That is the part used in that "Atari 2600 games in an
Atari joystick" toy product.

There was one other vendor that told us about '816s, I think it might have
been Sonix. Not sure on that one, though.

--
-- Lewin A.R.W. Edwards (http://www.zws.com /)
Learn how to develop high-end embedded systems on a tight budget!
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Re: 2500AD C compiler for 6502
On Tue, 11 Nov 2003 17:55:53 -0500, Jim McGinnis

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Last I knew it was the Western Design Center.

George

Re: 2500AD C compiler for 6502

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Jim McGinnis' responses on this subject fit with my understanding of
Sunplus. If you read their datasheets, you'd see why they are afraid of
letting everyone read them--the datasheets create almost as many
questions as they answer.

Just to be sure no one gets the wrong idea, the cc65 owner is in the
right here. Sunplus considers their datasheets confidential, strange as
that may seem. cc65 cannot incorporate Sunplus support without Sunplus'
permission.

- Wallace


Re: 2500AD C compiler for 6502
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Last I checked (this was ~14 months ago), Sunplus had a very odd way
of compiling code. They use an off-the-shelf 6502 assembler trained
not to use certain registers that aren't implemented in certain of
their cutdown cores, and then they run a utility over the object code
to backpatch some of the opcodes and perform retrospective address
fixups.

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Sunplus supplies the toy market. Support is nonexistent in this
market. Incomprehensible, unreliable and guaranteeably buggy tools are
the norm. Generally it doesn't matter because you just give your rep
wave files and a flowchart and some $0.05-per-week laborer in the code
mines of China figures out how to get it 80% working, which is good
enough.

Re: 2500AD C compiler for 6502
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Remember the TI99?  Some companies like to demonstrate their
incompetence so that there's no question about their abilities...

I can't imagine anyone being able to enforce a copyright of
instruction mnemonics.  This is akin to trying to enforce a
copyright of the Latin alphabet.  [Maybe that's a way to get
rid of all the superfulous "E"s in English words -- I'll just
copyright the letter E and refuse to allow anyone to use it!]

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Re: 2500AD C compiler for 6502
oN 10-Nov-03, Wallace White said:

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No one needs permission to emit object code. And if the issue is
emitting assembly source, then even if SunPlus copyright their
assembler mnemonics, nothing prevents altering the syntax to take them
out of conflict.

Sounds more like the author doesn't *want* to do it.

--
Bill
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