Re: Zilog 8530 maxspeed?

["Eddie C. Dost" <ecd@skynet.be>]

> 	Hi all! Has somebody succeeded in using speeds higher than 38400bps
> 	through Zilog 8530 serial controller (i.e. almost all sun4m machines).
> 	I have no problems with 115200bps on sun4u with Siemens 82532,
> 	but it seems 38400 is max for Z8530. Or am I missing something?

The chip can do 76800bps, with an error rate depending on CPU speed
behind it. But this is not really worth anything, as modems don't support
that speed. This all depends on the the input clock given to the chip
on sun boards.

You can get faster as that by letting the chip do different bit samplings,
i.e. only 4 sample interval per bit, but this dramatically increases the
error rate on async interfaces (which makes it unusable with modems, again).

All in all 38400 is it.


Eddie C. Dost
ecd@skynet.be