Navtel 9460 Protocol Analyzer info?

Scott Stevens chenmel at earthlink.net
Thu Apr 14 18:49:29 CDT 2005


On Thu, 14 Apr 2005 01:23:03 -0400 (EDT)
der Mouse <mouse at rodents.montreal.qc.ca> wrote:

> >>> (not gonna wire two 6402 UARTS to my SYM-1 and [...])
> >> How about one Z8530?  :-)  [it's a DUART, for the Zilog-impaired]
> > The 8530 is a useful part for dedicated purposes, but isn't it
> > severely bandwidth cramped?
> 
> I don't think so, not per se.
> 
> > I am thinking that it's the serial chip in the Sparcstations,
> > correct me if I'm wrong.
> 
> No, that's right as far as it goes - most SPARCstations, at least.
> 
> > A few years ago I was pondering making a 'dialup connecting system
> > with NAT server' out of a SparcStation Classic (the little lunchbox
> > type Sparc).
> 
> Well, _one_ of the lunchbox SPARCs.  (The others are the IPC, the IPX,
> and the LX.)
> 

Yes.  My wording was crude and unclear.  I also have multiple IPC's,
IPX's and an LX.  I think the LX is the one I consider the best of the
form-factor.

> > I discovered quickly that the serial ports on the Sparc are VERY
> > speed constrained because of the 8530 chip.  It would have been
> > impossible to connect my USB Courier V-everything modem to it at,
> > say 57,600 baud, because the 8530 just plain won't go that fast.
> 
> While this is true of the 8530 *as used in the SPARCstations*, this is
> largely because of the clock Sun chose to drive it with.  Use a faster
> clock and your baud rate cap goes up correspondingly.  (Presumably
> there is a limit on the clock rate, but I don't know what it is; I'm
> fairly sure it's well above what Sun uses, at least.)

I guess my comment was incorrect in that I was speaking of how the chip
functions in Sun hardware, as above.  I suspect the chip can 'scream' if
fed the right clock.

I'm also prejudiced because a few years back I worked in a team on a
Intel 80296 based telemetry project that included an 8530 in the design.
 I never had to touch that code, but one of the guys who did absolutely
despised the 8530.  I took the liberty of handing him a copy of the
NetBSD code for the chip, which I think helped him understand it a
little better.  If I'm not wrong (from my cursory glance over the
datasheet) it's a very stateful part that the programmer has to be well
versed in the care and feeding of.  I probably WOULD be better
acquainted with the chip, but the tube of 8530's that I once purchased
on eBay, AND paid for, were never delivered by the seller.  heh.



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