On Sun, 3 Apr 2022 01:06:24 +0300, Dimiter_Popoff <dp@tgi-sci.com>
wrote:

>On 4/2/2022 23:50, Joe Gwinn wrote:
>> On Sat, 2 Apr 2022 22:15:00 +0300, Dimiter_Popoff <dp@tgi-sci.com>
>> wrote:
>>
>>> On 4/2/2022 21:51, Joe Gwinn wrote:
>>>> On Sat, 2 Apr 2022 21:38:30 +0300, Dimiter_Popoff <dp@tgi-sci.com>
>>>> wrote:
>>>>
>>>>> On 4/2/2022 20:47, John Larkin wrote:
>>>>>> On Sat, 2 Apr 2022 20:33:11 +0300, Dimiter_Popoff <dp@tgi-sci.com>
>>>>>> wrote:
>>>>>>
>>>>>>> On 4/2/2022 19:52, John Larkin wrote:
>>>>>>>> On Sat, 2 Apr 2022 18:54:50 +0300, Dimiter_Popoff <dp@tgi-sci.com>
>>>>>>>> wrote:
>>>>>>>>
>>>>>>>>> On 4/2/2022 1:37, John Larkin wrote:
>>>>>>>>>> On 1 Apr 2022 22:28:41 GMT, Uwe Bonnes
>>>>>>>>>> <bon@hertz.ikp.physik.tu-darmstadt.de> wrote:
>>>>>>>>>>
>>>>>>>>>>> John Larkin <jlarkin@highland_atwork_technology.com> wrote:
>>>>>>>>>>>> We're designing a biggish dual power supply, and the customer wants
>>>>>>>>>>>> remote sense. We'd add a small D9 connector or something for the four
>>>>>>>>>>>> sense inputs.
>>>>>>>>>>>>
>>>>>>>>>>>> This seems non-trivial. The supply should work normally if the rs pins
>>>>>>>>>>>> are not connected. We could put 50 ohm or somesuch resistors from the
>>>>>>>>>>>> main outputs to the rs pins, and then drive a high-z feedback circuit.
>>>>>>>>>>>>
>>>>>>>>>>>> If the two supplies are paralleled, the customer would use just two
>>>>>>>>>>>> sense wires.
>>>>>>>>>>>>
>>>>>>>>>>>> If rs is connected wrong, the supply can go bonkers or we could fry
>>>>>>>>>>>> the 50 ohm resistors.
>>>>>>>>>>>>
>>>>>>>>>>>> Sounds like we need current limiters and maybe diodes and maybe FPGA
>>>>>>>>>>>> logic.
>>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>> Why FPGA? Why not some uC?
>>>>>>>>>>
>>>>>>>>>> Every plugin board in this box has an FPGA. We need to do a lot of
>>>>>>>>>> signal processing. The isolated ADCs are ADUM7703 delta-sigmas with a
>>>>>>>>>> 20 MHz bit rate, which need a heap of decimation processing. We'll do
>>>>>>>>>> some 100 Mbit communications with the motherboard too.
>>>>>>>>>>
>>>>>>>>>> The little Trion FPGAs are about $10. We could even run a riscV
>>>>>>>>>> processor inside.
>>>>>>>>>>
>>>>>>>>>
>>>>>>>>> Thanks for mentioning these Trion FPGA-s, they look very interesting
>>>>>>>>> to me.
>>>>>>>>> Do you have any impression on their software licensing? I saw they
>>>>>>>>> sell it at $35 but does it turn into yet another subscription
>>>>>>>>> after some time?
>>>>>>>>
>>>>>>>> I'll ask my FPGA guy. I get the impression that it's not bad.
>>>>>>>>
>>>>>>>> They look cool. They are simple, with no ADC or high-end serdes or
>>>>>>>> things like that. They do have a dram controller (I think), lvds i/o,
>>>>>>>> schmitts, and a soft core riscV. 1Mbit of sram.
>>>>>>>>
>>>>>>>> We're about to make a test board that includes the T20F256C4. We plan
>>>>>>>> to measure a lot of stuff: pin-pin delays, Fmax on counters, LVDS
>>>>>>>> common-mode levels, delay-vs-Vcore and temperature, jitter, drive
>>>>>>>> strengths, things like that.
>>>>>>>>
>>>>>>>> We asked their support people about some details of using the LVDS
>>>>>>>> receivers at other levels, and they said "don't do that."
>>>>>>>>
>>>>>>>> I might make an ADC using an LVDS receiver as a comparator. The
>>>>>>>> minimal ADC would use three fpga pins and one external RC. That could
>>>>>>>> be v-to-f, pwm, delta-sigma, or single-slope. Fun.
>>>>>>>>
>>>>>>>> We've designed a flash manager with bootstrap and field upgrade and
>>>>>>>> such.
>>>>>>>>
>>>>>>>
>>>>>>> I am only after standard functions, and if their lvds will do for
>>>>>>> hdmi video out I'll be happy.
>>>>>>> What I feel nervous about are their design tools, looks like they
>>>>>>> are just $35 for now but how quickly can they become prohibitive
>>>>>>> for someone who does not sell millions of units.
>>>>>>
>>>>>> I never understood why FPGA vendors should charge for tools or use
>>>>>> insane licensing stuff. Makes more sense to just give it away, maybe
>>>>>> charge for support.
>>>>>>
>>>>>
>>>>> For many years - >20 - the electronica industry has been closing things
>>>>> down so only "politburo members" can do real development. Probably this
>>>>> is part of the same effort, FPGA vendors are interested in selling more
>>>>> chips but their large customers likely give them contracts against
>>>>> guarantees the tools will not be available to everybody.
>>>>
>>>> I'd bet it's an attempt to lock their customers in forever.
>>>
>>> Could be if it is a one time fee. Not sure what is in at the moment.
>>> But it started a long time ago so it is more likely to be the work
>>> of some 'visionary' to prevent the spread of knowledge which would
>>> cost them zillions. Look at how they closed down all things wifi,
>>> the first - prism or something - was documented etc. until it got
>>> bought out and hidden from there on. Even T10 started selling their
>>> documents many years ago... So far the rfc-s are not hidden, but for
>>> how long. Some Sauron seems to be be lurking in the shadows :-).
>>
>> A common problem.
>>
>>
>>>> A have MS Word 2016. Now MS Updater nags me to convert to Word365,
>>>> which is only by subscription. Strangely, Word 2016 is now developing
>>>> problems.
>>>>
>>>>
>>>>> I wonder if the $35 tool one can buy now will work on a PC with
>>>>> no internet connection. Guess I have only one way to know for sure.
>>>>
>>>> Very good question. And companies who want to protect their critical
>>>> computers and networks from ransomware attacks et al may well have an
>>>> air-gapped system.
>>>
>>> I am not concerned about our design critical stuff, it is all under
>>> dps. They got a foot in when xilinx bought the coolrunner some 20 years
>>> ago, we had a logic compiler I had written; the cpld-s we have now
>>> use an old xilinx tool, old enough to work with no internet.
>>
>> dps? Maybe Texas DPS?
>
>No, it is the OS run here, written/built on over the years by me.
>
>Just did a shot of what my screen can look like (usually not as
>cluttered):
>http://tgi-sci.com/misc/dps.gif

Ahh. That looks suspiciously like assembly code. The horror!

>>> Guess I'll try some of these (too?) new fpga-s out, once I have a
>>> working logic as I need it I typically don't need to change it for
>>> many years. They seem new enough to be yet preoccupied with how
>>> to change one time sales into subscription, guess we'll see.
>>> Their fpga-s look really good on paper for what I am after.
>>
>> I'd say that my system of the future is air-gapped, as it's too hard
>> to keep up with the threat of the day, so all Internet-dependent tools
>> are excluded from consideration, and see what happens. You may need
>> to stop talking to the sales droids to convince them that you mean it.
>
>I don't have the muscle to make them change policy so I try - have been
>doing if for nearly 30 years now - to just be independent on software
>written by anyone but me.

There are lots of customers with air-gapped systems. The point of the
query is to force the sales droid to tell you how to get that option,
or admit (through clenched teeth) that they do not support that
option.

> The one thing in our products we cannot
>reproduce without a wintel PC is a jedec file for a coolrunner CPLD,
>xilinx would not disclose its insides (we had a tool for it while
>it was Philips). Now I guess I'll settle for using someone else's
>fpga tool... Once I have the binary and a supply of silicon - which
>in our case it not large at all to be even a lifetime supply - I'll
>still have things under control I guess.

Hmm. War story: Twenty years ago, I worked with a small company
whose chief designer had been a cryptographer at NSA.

The FPGA design program (don't recall which one) did not allow one to
fix the identity and location of the I/O pins, so every FPGA program
spin randomly scrambled the pins, which raised havoc with the PC board
layout, and so on. The FPGA design program had closed file formats,
so the designer could not manually force things.

So the designer's inner cryptographer came out - he cracked the file
format, if I recall using differential cryptanalysis methods, and then
he could manually edit the files to maintain pin locations from spin
to spin.

..<https://en.wikipedia.org/wiki/Differential_cryptanalysis>

>> War story: In the early 1980s the transition to UNIX operating
>> systems and computer platforms began. I was assailed with sales teams
>> trying to convince me that their proprietary computer platform was so
>> much better than those UNIX toys that no real man would consider UNIX.
>> My answer was to take them on a tour of a storage room that was piled
>> to the ceiling with the boxes that a few hundred UNIX computers had
>> come in (being saved for delivery to the ultimate customer), and
>> intoning that this was the future. None of those proprietary vendors
>> survive.
>
>Well unix is a huge thing of course, most of the internet protocols
>have been done under it etc., but I am no unix person. When I have to
>use a unix command line I manage just the basics, if man works it is
>better... I remember some 10 years back I was trying to make a laptop
>dual-boot (xp and linux) and sector 0 was constantly polluted.
>Luckily I had made a copy of it prior to that using a boot CD and
>dd... :-). Was nicely surprised you could do such things
>not only under dps (it is not called dd there, just copy to device
>in non-file mode, does the same).

Yeah. In those days, each OS assumed that it owned the world, and
would stomp anything else. It was not by intent, at least not
initially, because nobody was trying to implement dual boot, in turn
because it would be pointless, as each OS was written to a specific
instruction set architecture. The emergence of UNIX undermined that
simpler world.

Joe Gwinn