[krw]

ORCAD is stuck in a time warp... it's had relatively few bugs fixed nor
features added in more than 5 years now. It is of course usable, but I'm
fairly certain that Cadence is getting very few new orders for ORCAD -- it's
people on maintenance (or I suppose purchasing more licenses if they already
have some) that keeps it alive. I believe they've actually dropped the price
in the past few years, recognizing that it's slowly losing value as it largely
lies around on life support.

The only good things I can say about it are more or less the same
reasons I use WinBlows. It works, sorta and there is a lot of
industry support. OTOH, the main reason I use it is that it's what
the boss bought.

 

[krw]

But anyone who uses Crapture deserves it ;-)

Deserves to get paid for using it. ;-)

 

[krw]

Indeed, but for many engineers the choice comes down to, "these are the tools
we have, if you don't like them, you know where the door is."

Pretty much. I actually bought 9.1 (in '98, IIRC).

Just wait for ObamaCAD... it'll promise to address any and all schematic
capture needs while outlawing any private tools.

Hope and ECO?

 

[Jim Thompson]

Deserves to get paid for using it. ;-)

I have a copy, only because some clients actually request their
documentation in Crapture format. Fortunately I can convert to
Crapture directly from PSpice (nee Microsim) Schematics... one of the
most user-friendly tools ever devised... and it does hierarchical
_gloriously_!

...Jim Thompson
--
| James E.Thompson, P.E. | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona 85048 Skype: Contacts Only | |
| Voice480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon at http://www.analog-innovations.com | 1962 |

I love to cook with wine Sometimes I even put it in the food

 

[krw]

Sounds pretty good.


Have the recpetionist manually duplex for you?

SWMBO wouldn't doesn't like that sort of talk. Oh, you meant at work!
;-) Nope, no receptionist.

1920x1080 23+" monitors are <$200 these days (e.g.,
http://www.newegg.com/Product/Product.aspx?Item=N82E16824009179 ) -- an
excellent value, IMO. 1920x1200 commands a significant premiuim for some odd
reason, as do models that allow the display to rotate, but still... my first
"big monitor" was a Viewsonic P815 21" CRT which I thought was "a good deal"
at $1500 over a decade ago now. Amazing how inexpensive this stuff has
become...

I bought a 24" 1920x1200 LCD monitor two years ago for $270. I've
seen it since for $240. I was tempted to buy one and bring it to
work, but then woke up. Sure they're cheap, but bosses are even
cheaper. Back when I was contracting, I told my boss that even at a
1% productivity gain, a second monitor was a break even in a month or
two. He wasn't impressed.

 

[krw]

[...]

Turtles?

I believe it comes from the Bhudist's vision of the Earth being
supported on the back of a turtle. Then, what is the turtle standing
on? Why another turtle! It's turtles all the way down.

http://www.search.com/reference/Turtles_all_the_way_down

Ah, yes

Power supplies normally get connected on globals.

Not in ultrasound machines.

Why? Power supplies make a mess of schematics and add little
information.

Easy: Have a script plot sheet numbers into all the blocks. Then you
just turn to page 37 if you want to see the first eight channels of a
beamformer. I've done lots of "dead tree" design reviews in the 80's and
90's. Mostly because projector bulbs couldn't always be trusted and also
so that people could jot notes into the schematic.

^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Exactly.

I'd have to see how that annotation works. I'm still not so sure
about flipping back and forth when tracking a signal through the
system. We'll see.

Question: How do you deal with connectors? I'm thinking along the
lines of a board mounted cable connector. DO you put them on separate
pages even if they only have one source/sink? I have a switching
network that would reduce to the control inputs if I made it a
hierarchical block.

There is no other way to fully understand and comprehend how an
ultrasound system works, from the schematic level. A flat sheet
structure would consist of 200 or more sheets, impossible to navigate.

I'm used to an entire cabinet of schematics. ;-)

[...]


Quite small. A hundred full time employees (give or take), more
during the summer and early fall. The engineering department is two
hardware engineers, three firmware types, a layout engineer,
mechanical engineer, technician, admin, and a manager.

That's a small engineering group. We were in the high-tech world,
production very much automated, so our division of about 100 people
alone had more than a dozen design engineers. Cost was critical so when
el presidente wanted me to run a division I had very few conditions but
integrating engineering into the MRP system was one.
That's the one thing I don't understand with this company. Every time
I mention it I get a "yeah, it would be nice to have" answer. I'm not
even asking for real-time numbers. Next time the owner asks for cost
reductions (and he will soon) I'll sure have an answer.

Sometimes lessons need to be learned the hard way, even on a corporate
level ;-)

Not so much "the hard way" (the world isn't going to end), but let's
make a deal... "You want to save money and I want to know how much of
*your* money I'm spending. Deal or no deal?"

More successful is usually the informal method: An evening in the pub
with the CEO and the CFO. Especially the CFO will catch on to the idea,
fast.

Don't think we have a CFO, or he's the same guy as the COO (the IT
people are next to useless here). The owner is pretty hands on, so
he's the one I have to get interested. Have never been out to a pub
with any of them though. I don't suppose distys count? ;-)

 

[UltimatePatriot]

Indeed, but for many engineers the choice comes down to, "these are the tools
we have, if you don't like them, you know where the door is."

Just wait for ObamaCAD... it'll promise to address any and all schematic
capture needs while outlawing any private tools.

And in the end, it won't work either. Just like Obama himself.

 

[Joerg]

[...]

Not in ultrasound machines.

Why? Power supplies make a mess of schematics and add little
information.

For example, there are intricate phase-locked balancing mechanisms that
make sure that any ever so slight sag is 100% synchronous to the Doppler
PRF. One must understand that in order to debug noise issues and so on.
Just a big block saying "100V/500mA supply" doesn't help. If you didn't
use such load balancing but wanted to just make it's "stiff enough"
you'd need a Mack truck to deliver the machine ;-)

^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Exactly.

I'd have to see how that annotation works. I'm still not so sure
about flipping back and forth when tracking a signal through the
system. We'll see.

It's much worse in a flat sheet structure because you'd have no overview
how cable harnesses are organized. Because they can't easily be shown. I
get a lot of flat sheet structures from clients for review and
optimization and this easily adds a few hours to the final bill.

Question: How do you deal with connectors? I'm thinking along the
lines of a board mounted cable connector. DO you put them on separate
pages even if they only have one source/sink? I have a switching
network that would reduce to the control inputs if I made it a
hierarchical block.

Usually those are on the top page, together with a reasonable amount of
functional blocks. Then reviewers or new engineers can see where which
lines go. Best to draw in all wires and buses and not just place little
islands "netlist-style". Much easier to comprehend.

There is no other way to fully understand and comprehend how an
ultrasound system works, from the schematic level. A flat sheet
structure would consist of 200 or more sheets, impossible to navigate.
I'm used to an entire cabinet of schematics. ;-)

[...]


Quite small. A hundred full time employees (give or take), more
during the summer and early fall. The engineering department is two
hardware engineers, three firmware types, a layout engineer,
mechanical engineer, technician, admin, and a manager.

That's a small engineering group. We were in the high-tech world,
production very much automated, so our division of about 100 people
alone had more than a dozen design engineers. Cost was critical so when
el presidente wanted me to run a division I had very few conditions but
integrating engineering into the MRP system was one.
That's the one thing I don't understand with this company. Every time
I mention it I get a "yeah, it would be nice to have" answer. I'm not
even asking for real-time numbers. Next time the owner asks for cost
reductions (and he will soon) I'll sure have an answer.
Sometimes lessons need to be learned the hard way, even on a corporate
level ;-)
Not so much "the hard way" (the world isn't going to end), but let's
make a deal... "You want to save money and I want to know how much of
*your* money I'm spending. Deal or no deal?"

More successful is usually the informal method: An evening in the pub
with the CEO and the CFO. Especially the CFO will catch on to the idea,
fast.

Don't think we have a CFO, or he's the same guy as the COO (the IT
people are next to useless here). The owner is pretty hands on, so
he's the one I have to get interested. Have never been out to a pub
with any of them though. ...

What? No pubs, no outings, no pool parties? Hmm, that was always
different at the places I worked at. A couple days ago we had the dog of
one client's president here, and later that night when they picked him
up we had a few beers together.


I don't suppose distys count? ;-)


Nope

 

[krw]

I have a copy, only because some clients actually request their
documentation in Crapture format. Fortunately I can convert to
Crapture directly from PSpice (nee Microsim) Schematics... one of the
most user-friendly tools ever devised... and it does hierarchical
_gloriously_!

I use a copy because my boss tells me to. The rest doesn't matter.

 

[krw]

krw wrote:

[...]

What I mean is this typical scenario, example ultrasound machine:

Top level diagram with a dozen blocks and all the interconnect buses.
Beamformer, pulse processor, Doppler detector, video processor, power
supply and so on.
Power supplies normally get connected on globals.

Not in ultrasound machines.

Why? Power supplies make a mess of schematics and add little
information.

For example, there are intricate phase-locked balancing mechanisms that
make sure that any ever so slight sag is 100% synchronous to the Doppler
PRF. One must understand that in order to debug noise issues and so on.
Just a big block saying "100V/500mA supply" doesn't help. If you didn't
use such load balancing but wanted to just make it's "stiff enough"
you'd need a Mack truck to deliver the machine ;-)

Then it's not a "power supply". What do you do for logic/analog
supplies (and ground)? Do you wire them explicitly or do you use an
implicit global?

It's much worse in a flat sheet structure because you'd have no overview
how cable harnesses are organized. Because they can't easily be shown. I
get a lot of flat sheet structures from clients for review and
optimization and this easily adds a few hours to the final bill.

Cable harnesses? Hmm, no cable harnesses on the boards. ;-)

Are you saying that you show physical relationships on schematics? I
do with decoupling, sorta.

Usually those are on the top page, together with a reasonable amount of
functional blocks. Then reviewers or new engineers can see where which
lines go. Best to draw in all wires and buses and not just place little
islands "netlist-style". Much easier to comprehend.

The problem is that I have a pile of connectors and few busses. The
connectors are all differential audio so putting them into busses is a
problem. I've placed them in their own blocks but the top page is
still going to look like a bowl of spaghetti.

There is no other way to fully understand and comprehend how an
ultrasound system works, from the schematic level. A flat sheet
structure would consist of 200 or more sheets, impossible to navigate.
I'm used to an entire cabinet of schematics. ;-)

[...]


Quite small. A hundred full time employees (give or take), more
during the summer and early fall. The engineering department is two
hardware engineers, three firmware types, a layout engineer,
mechanical engineer, technician, admin, and a manager.

That's a small engineering group. We were in the high-tech world,
production very much automated, so our division of about 100 people
alone had more than a dozen design engineers. Cost was critical so when
el presidente wanted me to run a division I had very few conditions but
integrating engineering into the MRP system was one.
That's the one thing I don't understand with this company. Every time
I mention it I get a "yeah, it would be nice to have" answer. I'm not
even asking for real-time numbers. Next time the owner asks for cost
reductions (and he will soon) I'll sure have an answer.
Sometimes lessons need to be learned the hard way, even on a corporate
level ;-)
Not so much "the hard way" (the world isn't going to end), but let's
make a deal... "You want to save money and I want to know how much of
*your* money I'm spending. Deal or no deal?"

More successful is usually the informal method: An evening in the pub
with the CEO and the CFO. Especially the CFO will catch on to the idea,
fast.

Don't think we have a CFO, or he's the same guy as the COO (the IT
people are next to useless here). The owner is pretty hands on, so
he's the one I have to get interested. Have never been out to a pub
with any of them though. ...

What? No pubs, no outings, no pool parties? Hmm, that was always
different at the places I worked at. A couple days ago we had the dog of
one client's president here, and later that night when they picked him
up we had a few beers together.

Last Nevember (still nice weather they have a party for the
families in the parking lot. Other than that, not so much. They did
have extra tickets to Braves games a couple of times. The last time
they provided transportation too, but July Saturday afternoons get a
bit warm in Atlanta.

I don't suppose distys count? ;-)


Nope

We have one who likes to stay in town at the university visitor's
center. He's had us out for pizza and beer (I did eat the pizza). ;-)

 

[Joerg]

krw wrote:

[...]

For example, there are intricate phase-locked balancing mechanisms that
make sure that any ever so slight sag is 100% synchronous to the Doppler
PRF. One must understand that in order to debug noise issues and so on.
Just a big block saying "100V/500mA supply" doesn't help. If you didn't
use such load balancing but wanted to just make it's "stiff enough"
you'd need a Mack truck to deliver the machine ;-)

Then it's not a "power supply". ...

They all supply power


What do you do for logic/analog

supplies (and ground)? Do you wire them explicitly or do you use an
implicit global?

GND always global, digital supplies mostly global except for phase-noise
sensitive stuff, analog supplies usually explicit.

[...]

Cable harnesses? Hmm, no cable harnesses on the boards. ;-)

I meant a true and full top-down architecture. The top sheet would be
the complete ultrasound machine and those things usually do contain
cable harnesses. Just like cars do.

Are you saying that you show physical relationships on schematics? I
do with decoupling, sorta.

I don't know what you mean by physical. I do try to be clear enough on
schematics so readers can say "Ah, that's the big cable over yonder".
After all, I often design stuff for companies who do not have an analog
engineer on staff which is why they "rent" me. But their engineers must
still be able to comprehend a detailed module or system spec.

The problem is that I have a pile of connectors and few busses. The
connectors are all differential audio so putting them into busses is a
problem. I've placed them in their own blocks but the top page is
still going to look like a bowl of spaghetti.

Well, how many is a pile?

[...]

Last Nevember (still nice weather they have a party for the
families in the parking lot. Other than that, not so much. They did
have extra tickets to Braves games a couple of times. The last time
they provided transportation too, but July Saturday afternoons get a
bit warm in Atlanta.

Well, that's a start. But don't leave it all just with the employer, we
organized most of the outings ourselves. Beach trips, keggers, pool
parties at someone's home and so on.

We have one who likes to stay in town at the university visitor's
center. He's had us out for pizza and beer (I did eat the pizza). ;-)

I'd have gone for the brewsky. At my first employer it has happened that
many of the cars were still in the lot after midnight because people
took cabs home, on account of too much booze.

 

[krw]

krw wrote:

[...]

Why? Power supplies make a mess of schematics and add little
information.

For example, there are intricate phase-locked balancing mechanisms that
make sure that any ever so slight sag is 100% synchronous to the Doppler
PRF. One must understand that in order to debug noise issues and so on.
Just a big block saying "100V/500mA supply" doesn't help. If you didn't
use such load balancing but wanted to just make it's "stiff enough"
you'd need a Mack truck to deliver the machine ;-)

Then it's not a "power supply". ...

They all supply power

If my product was a power supply, no, I wouldn't make its output a
global. If it used supplies for its internal circuitry, yes, it would
be a global. I have that instance in the widget I'm designing now. It
has an output that supplies power to a DUT. That output isn't a
global. ;-)

What do you do for logic/analog

GND always global, digital supplies mostly global except for phase-noise
sensitive stuff, analog supplies usually explicit.

I make them all global, though we show the pins on the symbols. I'm
trying to get them on separate pages even. The layout guy doesn't
like that (he's also the librarian).

[...]

Cable harnesses? Hmm, no cable harnesses on the boards. ;-)

I meant a true and full top-down architecture. The top sheet would be
the complete ultrasound machine and those things usually do contain
cable harnesses. Just like cars do.

Oh, we don't do higher level packaging in the schematics. That's done
on mechanical drawings. Not my job. ;-)

I don't know what you mean by physical.

Physical relationships of components. Maybe even dimensions. A cable
would "look" as it does in real life, with all the branches and
twists.

I do try to be clear enough on
schematics so readers can say "Ah, that's the big cable over yonder".
After all, I often design stuff for companies who do not have an analog
engineer on staff which is why they "rent" me. But their engineers must
still be able to comprehend a detailed module or system spec.

We do all of that in the (3D) mechanical drawings.

Well, how many is a pile?

More than 30 on the back (most are stacked). Another bunch of knobs,
displays, LEDs and stuff on the front. We're reusing most of the
mechanical stuff from another project so all that baggage comes along
too.

So far, I've put all of the stuff that goes to the DUT on one
hierarchical block and stuff to various other test equipment on
another two. That sorta works but the top page is nothing but lines.
It's not as bad as I thought it would be though.

[...]

Last Nevember (still nice weather they have a party for the
families in the parking lot. Other than that, not so much. They did
have extra tickets to Braves games a couple of times. The last time
they provided transportation too, but July Saturday afternoons get a
bit warm in Atlanta.

Well, that's a start. But don't leave it all just with the employer, we
organized most of the outings ourselves. Beach trips, keggers, pool
parties at someone's home and so on.

The Braves tickets were left-overs from customers. Our customers are
sorta into sports, since they're football coaches. ;-) I suppose we
gotta find a busybody to get all that stuff together.

I'd have gone for the brewsky. At my first employer it has happened that
many of the cars were still in the lot after midnight because people
took cabs home, on account of too much booze.

Not allowed anymore. :-( IBC is as strong as it gets. Over the last
couple of years I've volunteered to be the DD for such things more
than once.

 

[Joerg]

krw wrote: [...]


Why? Power supplies make a mess of schematics and add little
information.

For example, there are intricate phase-locked balancing mechanisms that
make sure that any ever so slight sag is 100% synchronous to the Doppler
PRF. One must understand that in order to debug noise issues and so on.
Just a big block saying "100V/500mA supply" doesn't help. If you didn't
use such load balancing but wanted to just make it's "stiff enough"
you'd need a Mack truck to deliver the machine ;-)
Then it's not a "power supply". ...

They all supply power

If my product was a power supply, no, I wouldn't make its output a
global. If it used supplies for its internal circuitry, yes, it would
be a global. I have that instance in the widget I'm designing now. It
has an output that supplies power to a DUT. That output isn't a
global. ;-)

You can do that but when several of the supplies are synchronized to
signals that originate in the innards of the machine this can get old.
Makes it difficult to understand for anyone but the original design
engineers.

[...]

Oh, we don't do higher level packaging in the schematics. That's done
on mechanical drawings. Not my job. ;-)

Cable harnesses aren't exactly mechanical in nature. One must understand
where which one goes and where it branches. When looking at wiring
diagrams for some cars it becomes obvious pretty quickly how that kind
of visibility can be screwed up.

Physical relationships of components. Maybe even dimensions. A cable
would "look" as it does in real life, with all the branches and
twists.

Ok, I rarely place dimensions in schematics, only where it helps folks
find a branch. Or to show what stuff is underneath a shield which
reduces the frustration level of younger service guys.

With decoupling I do that as well. Except for mundane circuitry such as
glue logic where there is just a bunch of 0.1uF on 3.3V in a corner of
the sheet.

We do all of that in the (3D) mechanical drawings.

More than 30 on the back (most are stacked). Another bunch of knobs,
displays, LEDs and stuff on the front. We're reusing most of the
mechanical stuff from another project so all that baggage comes along
too.

Those could still find room on one B-size sheet, unless too many of them
are 50-pinners or larger.

So far, I've put all of the stuff that goes to the DUT on one
hierarchical block and stuff to various other test equipment on
another two. That sorta works but the top page is nothing but lines.
It's not as bad as I thought it would be though.

It can make sense to put the connectors on the 2nd hierarchy level,
especially if they are on a common large panel which is a separate
sub-assy in production.

[...]

Don't think we have a CFO, or he's the same guy as the COO (the IT
people are next to useless here). The owner is pretty hands on, so
he's the one I have to get interested. Have never been out to a pub
with any of them though. ...
What? No pubs, no outings, no pool parties? Hmm, that was always
different at the places I worked at. A couple days ago we had the dog of
one client's president here, and later that night when they picked him
up we had a few beers together.
Last Nevember (still nice weather they have a party for the
families in the parking lot. Other than that, not so much. They did
have extra tickets to Braves games a couple of times. The last time
they provided transportation too, but July Saturday afternoons get a
bit warm in Atlanta.

Well, that's a start. But don't leave it all just with the employer, we
organized most of the outings ourselves. Beach trips, keggers, pool
parties at someone's home and so on.

The Braves tickets were left-overs from customers. Our customers are
sorta into sports, since they're football coaches. ;-) I suppose we
gotta find a busybody to get all that stuff together.

Mine would only have not so useful things to offer. Scalpels, syringes,
catheters and so on. But there was that steel company that had managed
to find a brandy with the exact same spelling of the company's name. So
they bought cases of that.

Not allowed anymore. :-( IBC is as strong as it gets. Over the last
couple of years I've volunteered to be the DD for such things more
than once.

I remember a high-tech place near Munich, Germany, where we had some die
bonding done. In the hallway there was a vending machine. No cans but
bottles like in the old days. Five columns to choose from:

1: Clear lemonade
2: Orange lemonade
3: Beer
4: Beer
5: Beer

That gave me a chuckle.

 

[krw]

Cable harnesses aren't exactly mechanical in nature. One must understand
where which one goes and where it branches. When looking at wiring
diagrams for some cars it becomes obvious pretty quickly how that kind
of visibility can be screwed up.

Cable *harnesses* are quite mechanical in nature. A cable on a
schematic may be just a description of pinouts, but a harness is a bit
more. I'd rather the mechanical drawings be done separately where the
CAD tools are designed for this.

Ok, I rarely place dimensions in schematics, only where it helps folks
find a branch. Or to show what stuff is underneath a shield which
reduces the frustration level of younger service guys.

With decoupling I do that as well. Except for mundane circuitry such as
glue logic where there is just a bunch of 0.1uF on 3.3V in a corner of
the sheet.

I don't put them in the corner of the sheet unless they're in the
corner of the board (placement doesn't matter). Otherwise, I show
them next to the device they're decoupling. What I want to do is have
a homogenous "gate" for each device with only the power supplies. I
can then place that "gate" on a separate page and get the power
supplies completely off the schematic page.

Those could still find room on one B-size sheet, unless too many of them
are 50-pinners or larger.

At .1" spacings I don't think I could fit them all on. Most (the ones
in question here) are 1/4" stacked jacks, so have about 20 pins per
pair (only three used, one of them ground). They're supposed to be
XLRs but they won't fit so I'll convert to XLRs on the patch cables.
It's a COTS cable so it should be fine.

It can make sense to put the connectors on the 2nd hierarchy level,
especially if they are on a common large panel which is a separate
sub-assy in production.

Today I increased the page size for the top level schematic from
26.5"x16.5" to 22"x34" (still printing on 11"x17") and rearranged the
partitions and it looks a lot better. I'll go in tomorrow and stitch
in the FPGA and I should have enough for a rough design review Monday.
I still won't have power or FPGA configuration (need the symbol from
the layout guy), but that's pretty straight forward.

Decoupling is my other problem here. The FPGA is an F324 (18x18-1mm
pitch) which has no Central Park for decoupling. Altera says to use
0402 and 0201 caps but our manufacturing will have a cow. 0603 is as
small as they go.

[...]


Don't think we have a CFO, or he's the same guy as the COO (the IT
people are next to useless here). The owner is pretty hands on, so
he's the one I have to get interested. Have never been out to a pub
with any of them though. ...
What? No pubs, no outings, no pool parties? Hmm, that was always
different at the places I worked at. A couple days ago we had the dog of
one client's president here, and later that night when they picked him
up we had a few beers together.
Last Nevember (still nice weather they have a party for the
families in the parking lot. Other than that, not so much. They did
have extra tickets to Braves games a couple of times. The last time
they provided transportation too, but July Saturday afternoons get a
bit warm in Atlanta.

Well, that's a start. But don't leave it all just with the employer, we
organized most of the outings ourselves. Beach trips, keggers, pool
parties at someone's home and so on.

The Braves tickets were left-overs from customers. Our customers are
sorta into sports, since they're football coaches. ;-) I suppose we
gotta find a busybody to get all that stuff together.

Mine would only have not so useful things to offer. Scalpels, syringes,
catheters and so on. But there was that steel company that had managed
to find a brandy with the exact same spelling of the company's name. So
they bought cases of that.

I bet those gifts were appreciated. ;O)

I remember a high-tech place near Munich, Germany, where we had some die
bonding done. In the hallway there was a vending machine. No cans but
bottles like in the old days. Five columns to choose from:

1: Clear lemonade
2: Orange lemonade
3: Beer
4: Beer
5: Beer

I was once snowed in, in a fire house in downtown Poughkeepsie NY. We
had 24" of sloppy snow and the police were just sending people around
the city in circles. Anyway, the firemen cleared everyone out of
cars, which were left as they sat, into the fire station. When I was
about to put *a* quarter into the coke machine, one of the firemen
told me to try the Dr. Pepper. Yep, a 3/4/5.

That gave me a chuckle.

That's common in Europe. Even IBM had beer in the cafeteria in
Germany and Wine in France. Such things were an instant termination
offense in the US. That and drugs were about the only way to get
fired.

 

[Joerg]

Cable *harnesses* are quite mechanical in nature. A cable on a
schematic may be just a description of pinouts, but a harness is a bit
more. I'd rather the mechanical drawings be done separately where the
CAD tools are designed for this.

I meant the cables in there

For clarity of the schematic I try to keep them together just like they
are in the harness.

I don't put them in the corner of the sheet unless they're in the
corner of the board (placement doesn't matter). Otherwise, I show
them next to the device they're decoupling. What I want to do is have
a homogenous "gate" for each device with only the power supplies. I
can then place that "gate" on a separate page and get the power
supplies completely off the schematic page.

Ugh, I never do that. Power symbols go right where the A-device is.
Placing the decoupling caps there is ideally the right method but
sometimes they do get in the way with digital stuff.

At .1" spacings I don't think I could fit them all on. Most (the ones
in question here) are 1/4" stacked jacks, so have about 20 pins per
pair (only three used, one of them ground). They're supposed to be
XLRs but they won't fit so I'll convert to XLRs on the patch cables.
It's a COTS cable so it should be fine.

Ok, if that's 30 stacks and not 30 connectors that could get too dense.

[...]

Decoupling is my other problem here. The FPGA is an F324 (18x18-1mm
pitch) which has no Central Park for decoupling. Altera says to use
0402 and 0201 caps but our manufacturing will have a cow. 0603 is as
small as they go.

Can't you put some on the other side and get away with 0603?

[...]

I was once snowed in, in a fire house in downtown Poughkeepsie NY. We
had 24" of sloppy snow and the police were just sending people around
the city in circles. Anyway, the firemen cleared everyone out of
cars, which were left as they sat, into the fire station. When I was
about to put *a* quarter into the coke machine, one of the firemen
told me to try the Dr. Pepper. Yep, a 3/4/5.

One quarter? That must have been in the 70's. Poughkeepsie sound like IBM.

That's common in Europe. Even IBM had beer in the cafeteria in
Germany and Wine in France. Such things were an instant termination
offense in the US. That and drugs were about the only way to get
fired.

I remember the good old days. Weller station to your right, scope in the
middle, beer to your left.

 

[krw]

I meant the cables in there

For clarity of the schematic I try to keep them together just like they
are in the harness.

Not sure I follow.

Ugh, I never do that. Power symbols go right where the A-device is.
Placing the decoupling caps there is ideally the right method but
sometimes they do get in the way with digital stuff.

That makes a mess of multi-gate devices. Which one do you put the
power pins on? Power pins (and decoupling) also gums up the logical
flow of the schematic.

At .1" spacings I don't think I could fit them all on. Most (the ones
in question here) are 1/4" stacked jacks, so have about 20 pins per
pair (only three used, one of them ground). They're supposed to be
XLRs but they won't fit so I'll convert to XLRs on the patch cables.
It's a COTS cable so it should be fine.

Ok, if that's 30 stacks and not 30 connectors that could get too dense.

[...]

Fifteen pairs of 1/4" connectors, plus a half dozen stacked RJ45s. It
works out fairly well down a level in the hierarchy since they're
grouped logically.

Can't you put some on the other side and get away with 0603?

Where? No Central Park in an FBGA. Altera suggests 0402s and 0201s
in between the vias but 0603s won't fit.

[...]

I was once snowed in, in a fire house in downtown Poughkeepsie NY. We
had 24" of sloppy snow and the police were just sending people around
the city in circles. Anyway, the firemen cleared everyone out of
cars, which were left as they sat, into the fire station. When I was
about to put *a* quarter into the coke machine, one of the firemen
told me to try the Dr. Pepper. Yep, a 3/4/5.

One quarter? That must have been in the 70's. Poughkeepsie sound like IBM.

It was a fire house. Yes, March '78. I did a 19 year sentence in IBM
P'ok (and another 14 in BTV). ;-)

I remember the good old days. Weller station to your right, scope in the
middle, beer to your left.

Never drank when I worked. When I lifted the first beer it was an
acknowledgement that I was done for the day.

 

[Joerg]

Not sure I follow.

There will be buses and wires that I deliberately run in parallel,
usually with a few dashed line ovals around on the outline layer (not
the net layer), plus some text such as "AC controller harness". Then
everyone will know that all those lines are inside that big blue hose
over there.

That makes a mess of multi-gate devices. Which one do you put the
power pins on? Power pins (and decoupling) also gums up the logical
flow of the schematic.

In logic sections I don't use power symbols, except in critical areas
like LO phase shifters. In the analog sections I make enough room for
them because much is decoupled individually and on another net because
of series filtering. On a multi-gate device power is always on unit A.

This is one reason I cannot use GPL software such as gEDA or Kicad
because they do not handle this correctly and the communities there do
not seem to grasp te importance of it.

I do try to be clear enough on
schematics so readers can say "Ah, that's the big cable over yonder".
After all, I often design stuff for companies who do not have an analog
engineer on staff which is why they "rent" me. But their engineers must
still be able to comprehend a detailed module or system spec.
We do all of that in the (3D) mechanical drawings.
Question: How do you deal with connectors? I'm thinking along the
lines of a board mounted cable connector. DO you put them on separate
pages even if they only have one source/sink? I have a switching
network that would reduce to the control inputs if I made it a
hierarchical block.

Usually those are on the top page, together with a reasonable amount of
functional blocks. Then reviewers or new engineers can see where which
lines go. Best to draw in all wires and buses and not just place little
islands "netlist-style". Much easier to comprehend.
The problem is that I have a pile of connectors and few busses. The
connectors are all differential audio so putting them into busses is a
problem. I've placed them in their own blocks but the top page is
still going to look like a bowl of spaghetti.

Well, how many is a pile?
More than 30 on the back (most are stacked). Another bunch of knobs,
displays, LEDs and stuff on the front. We're reusing most of the
mechanical stuff from another project so all that baggage comes along
too.

Those could still find room on one B-size sheet, unless too many of them
are 50-pinners or larger.
At .1" spacings I don't think I could fit them all on. Most (the ones
in question here) are 1/4" stacked jacks, so have about 20 pins per
pair (only three used, one of them ground). They're supposed to be
XLRs but they won't fit so I'll convert to XLRs on the patch cables.
It's a COTS cable so it should be fine.

Ok, if that's 30 stacks and not 30 connectors that could get too dense.

[...]

Fifteen pairs of 1/4" connectors, plus a half dozen stacked RJ45s. It
works out fairly well down a level in the hierarchy since they're
grouped logically.

That would fit on one sheet.

Where? No Central Park in an FBGA. Altera suggests 0402s and 0201s
in between the vias but 0603s won't fit.

On the opposite side of the circuit board.

[...]

Never drank when I worked. When I lifted the first beer it was an
acknowledgement that I was done for the day.

Sometimes when working very late I'll have a nice brewsky. Only the good
stuff. But only one, and I usually nurse it a long time. Otherwise the
senses dull.

 

[krw]

There will be buses and wires that I deliberately run in parallel,
usually with a few dashed line ovals around on the outline layer (not
the net layer), plus some text such as "AC controller harness". Then
everyone will know that all those lines are inside that big blue hose
over there.

Perhaps I'm not seeing it because I don't build schematics at higher
level assemblies. On board schematics I'll use some hints (like
running differential pairs together as long as possible - to the point
of looking strange) but usually use only attributes.

In logic sections I don't use power symbols, except in critical areas
like LO phase shifters. In the analog sections I make enough room for
them because much is decoupled individually and on another net because
of series filtering. On a multi-gate device power is always on unit A.

THen when you swap gates in layout you redraw the schematic to follow
the "A-gate"? That's what we do and it's *fugly*. It's better than
putting them on all gates, but not much. I'd rather sequester them on
a separate page and have all the "op-amps" look the same. DRC will
quickly tell me if any are left out.

This is one reason I cannot use GPL software such as gEDA or Kicad
because they do not handle this correctly and the communities there do
not seem to grasp te importance of it.

How do they do it?

I do try to be clear enough on
schematics so readers can say "Ah, that's the big cable over yonder".
After all, I often design stuff for companies who do not have an analog
engineer on staff which is why they "rent" me. But their engineers must
still be able to comprehend a detailed module or system spec.
We do all of that in the (3D) mechanical drawings.
Question: How do you deal with connectors? I'm thinking along the
lines of a board mounted cable connector. DO you put them on separate
pages even if they only have one source/sink? I have a switching
network that would reduce to the control inputs if I made it a
hierarchical block.

Usually those are on the top page, together with a reasonable amount of
functional blocks. Then reviewers or new engineers can see where which
lines go. Best to draw in all wires and buses and not just place little
islands "netlist-style". Much easier to comprehend.
The problem is that I have a pile of connectors and few busses. The
connectors are all differential audio so putting them into busses is a
problem. I've placed them in their own blocks but the top page is
still going to look like a bowl of spaghetti.

Well, how many is a pile?
More than 30 on the back (most are stacked). Another bunch of knobs,
displays, LEDs and stuff on the front. We're reusing most of the
mechanical stuff from another project so all that baggage comes along
too.

Those could still find room on one B-size sheet, unless too many of them
are 50-pinners or larger.
At .1" spacings I don't think I could fit them all on. Most (the ones
in question here) are 1/4" stacked jacks, so have about 20 pins per
pair (only three used, one of them ground). They're supposed to be
XLRs but they won't fit so I'll convert to XLRs on the patch cables.
It's a COTS cable so it should be fine.

Ok, if that's 30 stacks and not 30 connectors that could get too dense.

[...]

Fifteen pairs of 1/4" connectors, plus a half dozen stacked RJ45s. It
works out fairly well down a level in the hierarchy since they're
grouped logically.

That would fit on one sheet.

The connectors alone will barely fit.

On the opposite side of the circuit board.

The FPGA is on the opposite side. ;-) The vias are on the side I'm
talking about. ;-)

[...]

Never drank when I worked. When I lifted the first beer it was an
acknowledgement that I was done for the day.

Sometimes when working very late I'll have a nice brewsky. Only the good
stuff. But only one, and I usually nurse it a long time. Otherwise the
senses dull.

One is (never) enough.

 

[Joerg]

[...]

In logic sections I don't use power symbols, except in critical areas
like LO phase shifters. In the analog sections I make enough room for
them because much is decoupled individually and on another net because
of series filtering. On a multi-gate device power is always on unit A.

THen when you swap gates in layout you redraw the schematic to follow
the "A-gate"? That's what we do and it's *fugly*. It's better than
putting them on all gates, but not much. I'd rather sequester them on
a separate page and have all the "op-amps" look the same. DRC will
quickly tell me if any are left out.

I usually get it about right when drawing the schematic. Many of my
layouts are noise-critical so I kind of picture it in my head while
drawing. Else I can always re-annotate. Then either leave the power on
the C-device or clean it all up.

How do they do it?

They don't. IMHO gEDA's library editor doesn't have the proper means to
do it correctly in the first place. Then on re-annotate it really screws
up the instantiations, or slots as their community calls them. KiCad has
an excellent library editor, much better than gEDA. But on re-annotate
.... poof.

I mentioned it in both forums and in the gEDA group one of the leaders
kind of flew off the handle, not seeing why this is so important and
berating me not to bring this up all the time. Oh well, then I just
walked away. But I occasionally check back in because the idea of gEDA
is great.

[...]

The FPGA is on the opposite side. ;-) The vias are on the side I'm
talking about. ;-)

That truly being between a rock and a hard spot ;-)

[...]

That gave me a chuckle.
That's common in Europe. Even IBM had beer in the cafeteria in
Germany and Wine in France. Such things were an instant termination
offense in the US. That and drugs were about the only way to get
fired.
I remember the good old days. Weller station to your right, scope in the
middle, beer to your left.
Never drank when I worked. When I lifted the first beer it was an
acknowledgement that I was done for the day.

Sometimes when working very late I'll have a nice brewsky. Only the good
stuff. But only one, and I usually nurse it a long time. Otherwise the
senses dull.

One is (never) enough.

Well, then there is the occasional Schnaps

 

[krw]

krw wrote:

[...]

In logic sections I don't use power symbols, except in critical areas
like LO phase shifters. In the analog sections I make enough room for
them because much is decoupled individually and on another net because
of series filtering. On a multi-gate device power is always on unit A.

THen when you swap gates in layout you redraw the schematic to follow
the "A-gate"? That's what we do and it's *fugly*. It's better than
putting them on all gates, but not much. I'd rather sequester them on
a separate page and have all the "op-amps" look the same. DRC will
quickly tell me if any are left out.

I usually get it about right when drawing the schematic. Many of my
layouts are noise-critical so I kind of picture it in my head while
drawing. Else I can always re-annotate. Then either leave the power on
the C-device or clean it all up.

Choosing the gates is up to the layout guy. It's not just a matter of
back annotation, rather redrawing the schematics to show the power on
the new 'A' gate - messy. If it were just a matter of back annotation
it would be easy.

They don't. IMHO gEDA's library editor doesn't have the proper means to
do it correctly in the first place. Then on re-annotate it really screws
up the instantiations, or slots as their community calls them. KiCad has
an excellent library editor, much better than gEDA. But on re-annotate
... poof.

I guess I'd have to see it.

I mentioned it in both forums and in the gEDA group one of the leaders
kind of flew off the handle, not seeing why this is so important and
berating me not to bring this up all the time. Oh well, then I just
walked away. But I occasionally check back in because the idea of gEDA
is great.

[...]

Not so great if it doesn't work. ;-)

That truly being between a rock and a hard spot ;-)

Yep. I really liked the FPGA packages like the old FG680 where the
balls were only five or six rows deep, with only power and ground on
the inner couple of those. The center square was wide open for
decoupling and termination. Not so with the newer packages.

[...]


That gave me a chuckle.
That's common in Europe. Even IBM had beer in the cafeteria in
Germany and Wine in France. Such things were an instant termination
offense in the US. That and drugs were about the only way to get
fired.
I remember the good old days. Weller station to your right, scope in the
middle, beer to your left.
Never drank when I worked. When I lifted the first beer it was an
acknowledgement that I was done for the day.

Sometimes when working very late I'll have a nice brewsky. Only the good
stuff. But only one, and I usually nurse it a long time. Otherwise the
senses dull.

One is (never) enough.

Well, then there is the occasional Schnaps

One of the few drinks I didn't much like (as opposed to rum and gin,
which were enough to make me barf). I never drank much of the hard
stuff.