Luiz Carlos wrote:
>>I don't see a problem, but I'm not intimate with the '061 ezkit either.
> 
> 
> But Jim, Bittware designed the ADSP-21061 EZ-Kit Lite. Don't you remember? :)


Heh heh.  No, I don't.  I knew BittWare had done one of the ezkits, but 
it was before I started working here.

-- 
Jim Thomas            Principal Applications Engineer  Bittware, Inc
jthomas@bittware.com  http://www.bittware.com          (703) 779-7770
Getting an inch of snow is like winning ten cents in the lottery - Calvin

hi,

Theron Hicks wrote:
> Hello,
>     I have a sharc adsp-21061 ez-kit board and I would like to make two
> changes to it.
>     The first change is to use the second serial port to talk to a different
> A/D.  The problem with the A/D on the card is that it wants to be AC
> coupled.  I need DC data.  So I plan on hooking up an AD974 or AD977 to the
> second serial port.  Does anyone see a problem here?
>     The second problem is that I need some digital signals to control a few
> relays.  I suspect that I need to do some memory mapped I/O using an FPGA,
> etc. to decode the address, etc.  Is there an app note or something similar
> that shows the memory interface to do this?  I am sure I could figure it out
> myself, but if I can find it already done, that will reduce the probability
> of screw-ups on my part.  I really would prefer to get it right on the first
> trial.

look at the SHARC doc :
there are several /MS lines,
or "memory select" lines, which predecode
several memory banks. you can use them
for enabling a couple of 74LVC138 for example.

hope this helps,

YG

> Thanks,
> Theron Hicks
> 
> 

Theron Hicks wrote:

> Hello,
>     I have a sharc adsp-21061 ez-kit board and I would like to
>     make two
> changes to it.
>     The first change is to use the second serial port to talk to a
>     different
> A/D.  The problem with the A/D on the card is that it wants to be
> AC
> coupled.  I need DC data.  

I own another EZ-KIT board (21161) with another ADC.
However, my approach might work for you,too.

I just removed the serial capacitors next to the connectors, which 
did the decoupling.
Then I had to change a few resistors, so that the gain/offset values 
were correct. 
With these tiny changes, the built-in Sigma-Delta-Converter does a 
good job dealing with DC coupled signals.
The same works for the outputs. 
However,  be aware that the board might suffer from spurious 
currents creeping across your interface - check the complete 
design.

Bernhard

Luiz Carlos wrote:

> > I don't see a problem, but I'm not intimate with the '061 ezkit either.
>
> But Jim, Bittware designed the ADSP-21061 EZ-Kit Lite. Don't you remember? :)
>
> > Have you considered using the flag pins instead?
>
> Right. 21061 has 4 flag pins and they are all on connector J3.
>
> Luiz Carlos

Unfortunately, I have a lot more than 4 relays to control (Actual number is >16).
Although it is not fully designed, I expect that the total number of digital
outputs is about 20.  Not all these are relays but all are digital on-off type
signals.  The only reason for the DSP is the analog data collection and
processing.  The DSP is gross overkill except that it offers simple serial analog
I/O and also I happen to have one unused and sitting on my desk.

Thanks,
Theron

> I don't see a problem, but I'm not intimate with the '061 ezkit either.

But Jim, Bittware designed the ADSP-21061 EZ-Kit Lite. Don't you remember? :)

> Have you considered using the flag pins instead?

Right. 21061 has 4 flag pins and they are all on connector J3. 

Luiz Carlos

Theron Hicks wrote:
> Hello,
>     I have a sharc adsp-21061 ez-kit board and I would like to make two
> changes to it.
>     The first change is to use the second serial port to talk to a different
> A/D.  The problem with the A/D on the card is that it wants to be AC
> coupled.  I need DC data.  So I plan on hooking up an AD974 or AD977 to the
> second serial port.  Does anyone see a problem here?

I don't see a problem, but I'm not intimate with the '061 ezkit either.

>     The second problem is that I need some digital signals to control a few
> relays.  I suspect that I need to do some memory mapped I/O using an FPGA,
> etc. to decode the address, etc.  Is there an app note or something similar
> that shows the memory interface to do this?  I am sure I could figure it out
> myself, but if I can find it already done, that will reduce the probability
> of screw-ups on my part.  I really would prefer to get it right on the first
> trial.

Have you considered using the flag pins instead?

-- 
Jim Thomas            Principal Applications Engineer  Bittware, Inc
jthomas@bittware.com  http://www.bittware.com          (703) 779-7770
There are 10 kinds of people: the ones who understand binary code,
and the ones who don't.

Hello,
    I have a sharc adsp-21061 ez-kit board and I would like to make two
changes to it.
    The first change is to use the second serial port to talk to a different
A/D.  The problem with the A/D on the card is that it wants to be AC
coupled.  I need DC data.  So I plan on hooking up an AD974 or AD977 to the
second serial port.  Does anyone see a problem here?
    The second problem is that I need some digital signals to control a few
relays.  I suspect that I need to do some memory mapped I/O using an FPGA,
etc. to decode the address, etc.  Is there an app note or something similar
that shows the memory interface to do this?  I am sure I could figure it out
myself, but if I can find it already done, that will reduce the probability
of screw-ups on my part.  I really would prefer to get it right on the first
trial.

Thanks,
Theron Hicks