Replacement for XC4005E

On Saturday, June 30, 2012 12:48:18 AM UTC+12, Terry Brown wrote:
> Looks like I'll still have an issue interfacing to the 5V ISA bus on 
> PC104 stacks though, although the Xilinx devices have some 5V tolerant 
> inputs, and I guess I can translate the outputs, there aren't that many 
> apart from the data bus.

 You could use two different devices ? 
 The large IO count tends to bump you up the price curve anyway, so either 2 x 100 pin parts, or 100p + 44p.

 Use an 100p/44p Atmel CPLD for the Level shifting/5V IO and a 100p MachXO2 for the engine room stuff that will not fit into a smaller CPLD.

-jg

Jon Elson <jmelson@wustl.edu> wrote:

>Terry Brown wrote:
>
>  Automated assembly is really not an option because of the low
>> volumes, which we manage with three techs doing the assembly, and
>> external assembly wouldn't save any tech salary (because we need all
>> three anyway) but would just increase costs.
>> 
>
>> On the other hand, there's probably a good argument for embracing BGA
>> hand assembly anyway in this day and age, it would open up a bunch of
>> stuff that's not available in leaded packages, and things are going more
>> and more that way anyway.  Anyone have any experience with it?
>Well, the real problem with BGAs is there is no simple way to inspect the
>soldering.  With QFPs and such, a stereo zoom microscope for several
>hundred $ and a ring light is about all you need.

OTOH BGA usually solder well. I have good results with reworking BGAs
using a standard heat gun aka paint stripper.

-- 
Failure does not prove something is impossible, failure simply
indicates you are not using the right tools...
nico@nctdevpuntnl (punt=.)
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glen herrmannsfeldt <gah@ugcs.caltech.edu> wrote:

>rickman <gnuarm@gmail.com> wrote:
>
>(snip)
>> One final comment.  I resisted the switch from schematic to HDL back
>> in the day.  Now I would not touch schematic.  The single biggest
>> reason to use HDL is the vendor independence.  It makes it so easy to
>> switch from one line of devices to another.  Learning an HDL is not
>> really so tough, especially if you don't do software.  When I learned
>> I kept thinking it was like other software and it isn't.  It describes
>> hardware so the code works very differently.  If you need help with
>> that, I think I could be useful to you in getting up the learning
>> curve.  I've helped others before.
>
>I agree. For one, I prefer structural verilog and continuous 
>assignment, which looks less like software. 
>
>Also, it helps to have learned about digital logic before, or 
>not so long after, you start learning software programming
>language(s). 
>
>Think in terms of wires and gates, then write them down.

The problem with that method is that you limit yourself to making a
netlist manually. HDLs offer a lot of power which allows you to
describe a large amount of hardware with just a few lines of code.

-- 
Failure does not prove something is impossible, failure simply
indicates you are not using the right tools...
nico@nctdevpuntnl (punt=.)
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