ComputerVoltageSources

I don't understand why they don't have a datasheet.  It isn't rocket 
science.  However, there are a lot of strengths to this part.

It is available.

It is fast.  I am merging MIDI streams while scanning my bass pedals 
and sending MIDI (at 38,25 kbaud) and display data (at 57,600 kbaud) 
and running timer interrupts at 1 mS.  Not bad for basic.  I'm not 
sure we'd get that kind of performance out of other products and I do 
a lot of MIDI processing.

Hardware floating point.  I've benchmarked it and it is only slightly 
slower than integer performance.

I've verified the on-chip eeprom.  I've also verified the I2C input 
and output.

Positive and negative edge interrupts.  Great for capturing quick 
triggers.

The development environment works quite well.  I've got no issues with 
it. Always reliable.

Reasonable code space.  I was a bit concerned about adding 128 defined 
strings to display GM MIDI instruments but that program only took 12.5 
kbytes and I have 20 kbytes of code space left.

For me, code compatibility is pretty important but that's only because 
I have 32 programs and don't feel like figuring out all the nuances of 
a new compiler.

On the downside, the interrupts for the 3rd timer don't work in the 
current compiler and the include function doesn't work which requires 
each program to be stand alone.

As to the reset, they added a power-on reset chip.  I guess it is a 
nice feature as the PSIM doesn't always reliably reset (I added a 
capacitor to mine).  This circuit generates a 360 mS reset with fast 
edges so you can guarantee that all external devices reset.  I assume 
it would be described in the data sheet if there were one.  My issue 
was trying to reset it externally with a switch.  Not a good idea on a 
totem pole output.  I only noticed this as I plugged the part into a 
current design PCB that has a reset switch and noticed the difference 
in operation.

I actually see few risks with commiting this to copper as many of the 
interfaces / timing / etc. have been validated (MIDI, I2C, timer 
interrupts, edge interrupts, etc.) but that is just my humble opinion.

Dave


--- In ComputerVoltageSources@yahoogroups.com, "Grant Richter" 
<grichter@...> wrote:
>
> I still don't see a datasheet for the BasicAtomPro28M on the 
BasicMicro website.
> 
> There are questions about the reset circuitry and if the current dev 
system supports the 
> additional 4 analog inputs. Dave Brown seems to have one working, 
did you find anything 
> about the reset problem you were having?
> 
> I really have not had the time or money to buy a 28M and hand trace 
a schematic and test 
> the software.
> 
> It seems brash to commit to a copper board with the number of 
questions still remaining 
> about the processor core itself.
> 
> I think issuing a PC board with unresolved technical issues may do 
more harm than good.
> 
> Grant Richter
> 
> --- In ComputerVoltageSources@yahoogroups.com, Harry Bissell Jr 
<harrybissell@> 
> wrote:
> >
> > Last plan was that Grant was going to fax me a sketch
> > of the CPU schematic and I would draw it... then we
> > will proceed. I have not heard anything since, but
> > he's
> > prlly busy like me :^P
> > 
> > H^) harry
> > 
> > --- "Larry T." <larry@> wrote:
> > 
> > > Hello everyone
> > > 
> > > I'm just wondering if there is any kind of status
> > > update on the state
> > > of the main processor PCB layout?
> > > 
> > > Larry T.
> > > 
> > > 
> > > 
> > >
> >
>