On Thu, 10 Mar 2011 17:47:17 -0500, "Michael A. Terrell"
wrote:


Jim Thompson wrote:

On Thu, 10 Mar 2011 22:32:55 +0100, "Arie de Muynck"
wrote:


"Tom Del Rosso" wrote in message
m...

Arie de Muynck wrote:
"Arie de Muynck" wrote:
I do remember it. I saw it inside a TTL EXOR circuit, maybe the
7486. Two NPN's, E and B cross connected to open collector drivers
(A and B), output taken from connected collectors, with a pull-up.
At least it is symmetrical, but maybe not too fast.


A ---- E1 -- B2 pull-up
|
C1 -- C2 --+--- OUT

B ---- B1 -- E2

I was thinking of the same thing, but it was the TTL 8-bit parity
generator (don't remember the number), not the 7486. I think the parity
generator/checker used 8 gates.

Apparently Jim doesn't have discreets on his ASIC or he would have liked
this.

Maybe he just did not read this part of the thread. Or I'm blacklisted.
The beautiful symmetry should appeal to him.

And of course it needed some pull-ups on the O.C. drivers as well...

If it was driven by another like it, as in the parity tree. But couldn't
it be driven high and low? (IANAEE)

No, hard driving one input high, the other low would overdrive conducting
B-E junctions.
And you need to pull the E's low hard to get the output at a logic low
level.
The base is then driven though the other pull-up.

Now I think of it, this piece or RTL logic with a twist even looks nicer (2x
NPN):

|\ VCC
A --| -+------- E C -----+ |
|/ | B | (R)
\ /--(R)--+ | |
X +------+--- OUT
/ \--(R)--+ |
|\ | B |
B --| -+------- E C -----+
|/

A good bottle of dry white signed by Jim is OK to use this :-)

Arie

You missed the part where what I really need is two circuits, each
with input A, but one with output A and the other with output Abar,
delay to each output EQUAL.

What is your preference in dry white wine ?:-)

Unfortunately I'm on the wagon at the moment. Something untoward
going on in my colon. Colonoscopy scheduled for Tuesday. Damned
capitalist health care... 1 week delay (from Doctor's order) while I'm
weaned from anti-inflammatory which could cause bleeding ;-)


A week? It was over a year with the VA.

I know. That's a shame :-(

Once upon a time there was the GI Bill where servicemen were properly
rewarded for their sacrifices.

...Jim Thompson
--
| James E.Thompson, CTO | 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 |

Remember: Once you go over the hill, you pick up speed

Jim Thompson wrote:

You missed the part where what I really need is two circuits, each
with input A, but one with output A and the other with output Abar,
delay to each output EQUAL.

I thought the problem was unequal delays from one input to one output under
different conditions (other input is high or low).

This means that David Eather's mux idea is what you need. Since the mux
inputs are fixed, the gates can be simplified.


--

Reply in group, but if emailing add one more
zero, and remove the last word.

Jim Thompson wrote:
On Thu, 10 Mar 2011 09:00:01 -0600, Vladimir Vassilevsky
wrote:


Jim Thompson wrote:



Oh! How Larkinesque :-)
Could you put some values (and device dimensions) on that sketch ?:-)
Here is absolutely symmetrical XOR, it is also absolutely minimal :-)

http://www.abvolt.com/misc/xor.jpg


Vladimir Vassilevsky
DSP and Mixed Signal Design Consultant
http://www.abvolt.com

I'm not getting across to you. Describe how that works.

...Jim Thompson
I am also curious as how that is supposed to work.

Jim Thompson wrote:

On Thu, 10 Mar 2011 17:47:17 -0500, "Michael A. Terrell"
wrote:


Jim Thompson wrote:

On Thu, 10 Mar 2011 22:32:55 +0100, "Arie de Muynck"
wrote:


"Tom Del Rosso" wrote in message
m...

Arie de Muynck wrote:
"Arie de Muynck" wrote:
I do remember it. I saw it inside a TTL EXOR circuit, maybe the
7486. Two NPN's, E and B cross connected to open collector drivers
(A and B), output taken from connected collectors, with a pull-up.
At least it is symmetrical, but maybe not too fast.


A ---- E1 -- B2 pull-up
|
C1 -- C2 --+--- OUT

B ---- B1 -- E2

I was thinking of the same thing, but it was the TTL 8-bit parity
generator (don't remember the number), not the 7486. I think the parity
generator/checker used 8 gates.

Apparently Jim doesn't have discreets on his ASIC or he would have liked
this.

Maybe he just did not read this part of the thread. Or I'm blacklisted.
The beautiful symmetry should appeal to him.

And of course it needed some pull-ups on the O.C. drivers as well...

If it was driven by another like it, as in the parity tree. But couldn't
it be driven high and low? (IANAEE)

No, hard driving one input high, the other low would overdrive conducting
B-E junctions.
And you need to pull the E's low hard to get the output at a logic low
level.
The base is then driven though the other pull-up.

Now I think of it, this piece or RTL logic with a twist even looks nicer (2x
NPN):

|\ VCC
A --| -+------- E C -----+ |
|/ | B | (R)
\ /--(R)--+ | |
X +------+--- OUT
/ \--(R)--+ |
|\ | B |
B --| -+------- E C -----+
|/

A good bottle of dry white signed by Jim is OK to use this :-)

Arie

You missed the part where what I really need is two circuits, each
with input A, but one with output A and the other with output Abar,
delay to each output EQUAL.

What is your preference in dry white wine ?:-)

Unfortunately I'm on the wagon at the moment. Something untoward
going on in my colon. Colonoscopy scheduled for Tuesday. Damned
capitalist health care... 1 week delay (from Doctor's order) while I'm
weaned from anti-inflammatory which could cause bleeding ;-)


A week? It was over a year with the VA.

I know. That's a shame :-(

Once upon a time there was the GI Bill where servicemen were properly
rewarded for their sacrifices.


I was just transferred to one of the newest VA clinics in the
country, at 'The Villages' which is located south of Ocala, Fl. It has
100 exam rooms, MRI, Catscan, Ultrasound & X-ray. It has a dental
clinic, wound care, and optical department. They are supposed to offer
Lasik surgery later this year. It has two outpatient ORs, and a dozen
other services. The only difference between it and a hospital is that
there are no patient rooms. State law sets the number of patient rooms
in each area, but has no control over any other services. It also has
over 160 parking spaces, compared to the couple dozen at the last clinic
I was assigned to. I have lab work there on the 17th, and my first
doctor's appointment at the end of the month.


--
You can't fix stupid. You can't even put a Band-Aid™ on it, because it's
Teflon coated.

On Fri, 11 Mar 2011 07:23:37 -0500, "Michael A. Terrell"
wrote:


Jim Thompson wrote:

On Thu, 10 Mar 2011 17:47:17 -0500, "Michael A. Terrell"
wrote:


Jim Thompson wrote:

On Thu, 10 Mar 2011 22:32:55 +0100, "Arie de Muynck"
wrote:


"Tom Del Rosso" wrote in message
m...

Arie de Muynck wrote:
"Arie de Muynck" wrote:
I do remember it. I saw it inside a TTL EXOR circuit, maybe the
7486. Two NPN's, E and B cross connected to open collector drivers
(A and B), output taken from connected collectors, with a pull-up.
At least it is symmetrical, but maybe not too fast.


A ---- E1 -- B2 pull-up
|
C1 -- C2 --+--- OUT

B ---- B1 -- E2

I was thinking of the same thing, but it was the TTL 8-bit parity
generator (don't remember the number), not the 7486. I think the parity
generator/checker used 8 gates.

Apparently Jim doesn't have discreets on his ASIC or he would have liked
this.

Maybe he just did not read this part of the thread. Or I'm blacklisted.
The beautiful symmetry should appeal to him.

And of course it needed some pull-ups on the O.C. drivers as well...

If it was driven by another like it, as in the parity tree. But couldn't
it be driven high and low? (IANAEE)

No, hard driving one input high, the other low would overdrive conducting
B-E junctions.
And you need to pull the E's low hard to get the output at a logic low
level.
The base is then driven though the other pull-up.

Now I think of it, this piece or RTL logic with a twist even looks nicer (2x
NPN):

|\ VCC
A --| -+------- E C -----+ |
|/ | B | (R)
\ /--(R)--+ | |
X +------+--- OUT
/ \--(R)--+ |
|\ | B |
B --| -+------- E C -----+
|/

A good bottle of dry white signed by Jim is OK to use this :-)

Arie

You missed the part where what I really need is two circuits, each
with input A, but one with output A and the other with output Abar,
delay to each output EQUAL.

What is your preference in dry white wine ?:-)

Unfortunately I'm on the wagon at the moment. Something untoward
going on in my colon. Colonoscopy scheduled for Tuesday. Damned
capitalist health care... 1 week delay (from Doctor's order) while I'm
weaned from anti-inflammatory which could cause bleeding ;-)


A week? It was over a year with the VA.

I know. That's a shame :-(

Once upon a time there was the GI Bill where servicemen were properly
rewarded for their sacrifices.


I was just transferred to one of the newest VA clinics in the
country, at 'The Villages' which is located south of Ocala, Fl. It has
100 exam rooms, MRI, Catscan, Ultrasound & X-ray. It has a dental
clinic, wound care, and optical department. They are supposed to offer
Lasik surgery later this year. It has two outpatient ORs, and a dozen
other services. The only difference between it and a hospital is that
there are no patient rooms. State law sets the number of patient rooms
in each area, but has no control over any other services. It also has
over 160 parking spaces, compared to the couple dozen at the last clinic
I was assigned to. I have lab work there on the 17th, and my first
doctor's appointment at the end of the month.

Great! Good luck!

...Jim Thompson
--
| James E.Thompson, CTO | 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 |

Remember: Once you go over the hill, you pick up speed

Jim Thompson wrote:

Michael A. Terrell wrote:

I was just transferred to one of the newest VA clinics in the
country, at 'The Villages' which is located south of Ocala, Fl. It has
100 exam rooms, MRI, Catscan, Ultrasound & X-ray. It has a dental
clinic, wound care, and optical department. They are supposed to offer
Lasik surgery later this year. It has two outpatient ORs, and a dozen
other services. The only difference between it and a hospital is that
there are no patient rooms. State law sets the number of patient rooms
in each area, but has no control over any other services. It also has
over 160 parking spaces, compared to the couple dozen at the last clinic
I was assigned to. I have lab work there on the 17th, and my first
doctor's appointment at the end of the month.

Great! Good luck!


Thanks.


--
You can't fix stupid. You can't even put a Band-Aid™ on it, because it's
Teflon coated.

I had both ends done a few months ago. Nothing to it.

-----------

"Michael A. Terrell" wrote in message
m...
Thanks.


Jim Thompson wrote:
Great! Good luck!

m II wrote:

I had both ends done a few months ago. Nothing to it.


I had that colonoscopy several years ago. I slept through it.


--
You can't fix stupid. You can't even put a Band-Aid™ on it, because it's
Teflon coated.