ggs at shiresoft.com
Sat Mar 21 15:16:35 CDT 2009
On Mar 21, 2009, at 12:38 PM, Chuck Guzis wrote:
> On 21 Mar 2009 at 19:13, Tony Duell wrote:
>> Where the heck do you find employers who actually want people who can
>> design hardware for vintage computers ? One of those would solve
>> several of my problems...
> Nowadays many "hardware" positions seem to rely on one's ability to
> spew Verilog or VHDL and not know which end of the soldiering iron is
> the hot one.
Well, if the position is for designing ASICs or SOCs then it really is
more important to know how to write Verilog/VHDL. The likely hood of
actually having to "mod" the board is small, and they'll have
"technicians" for that and special stations with the fine temperature
controlled soldering irons plus optics to actually see the work. If
you're dealing with BGAs then reworks require fairly sophisticated
equipment (including being able to do X-Ray scans of the board to
check that all of the balls on the BGA are attached properly).
There's still a need to "dead bug" some fixes but that's becoming more
and more rare.
In reality most HW design these days is either with micro-controllers
or FPGA/ASICs. The traditional discrete TTL designs are pretty much
gone because the designs require small size/high integration or high
speed, which you can't really do with discrete TTL (or pick your logic
family). And if you're building a number of "widgets" you don't have
to have too high volumes before it really is cheaper to do FPGA/ASICs
rather than discrete.
I'm becoming a big fan of FPGAs for my designs for two principle
reasons. One is that I can simulate the design before committing it
to actual HW. This finds a huge number of issues. I can also write
comprehensive test cases that would be hard to do with actual
hardware. The other one is that if I do find something that slips
past the simulation then it's a simple problem to update FPGA image.
And no you don't have to have megabucks to do this. There are some
free (which is what I use) Verilog simulation tools that are quite
good (in my very limited experience) and each of the FPGA vendors have
free versions of their tools (they are after all trying to sell the
parts). Also, many part vendors (non-FPGA, ie RAMs, etc) provide
pretty comprehensive models for their parts to be used in simulation
so it isn't that hard to simulate an entire design encompassing many
TTFN - Guy
More information about the cctalk