Re: Zilog 8530 maxspeed?
> hm, but what about 57600bps? modems support it, all SW also. > Should I believe that Z8530 can do 38400, 76800 but NOT 57600bps? > With Siemens 82532 serial controller you can do all speeds w/o > any problem (except 76800 of course :) The Z8530 has no problems with that, but with a clock input of 4.9152MHz as on sparcs you can reach 57600 with 12.5% error, namely with a BRG divider setting of 1. This will give an overall post division by ((1 + 2) * 2) = 6, yielding a bitrate of 4915200 / 16 / 6 = 51200. Compared to that you will get 76800 with a divider setting of 0 like this: ((0 + 2) * 2 = 4, 4915200 / 16 / 4 = 76800. It's not only a problem of speed and fifo depth, but also a problem of integer mathematics. The SAB82532 has an input clock of 29.4912MHz on the Ultras, and also a much more flexible BRG divider section, so it can hit more common baud rates up to B921600 without problems (yes, I tested this). Eddie C. Dost [EMAIL PROTECTED]
Re: Zilog 8530 maxspeed?
hm, but what about 57600bps? modems support it, all SW also. Should I believe that Z8530 can do 38400, 76800 but NOT 57600bps? With Siemens 82532 serial controller you can do all speeds w/o any problem (except 76800 of course :) andrej - Quoted message begins - > > 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 > [EMAIL PROTECTED] - Quoted message ends - -- Andrej Misik - Sun Enterprise Services System Engineer email: [EMAIL PROTECTED] tel: +421 7 43429485, fax: +421 7 43429486, mobile: +421 903 406075 Sun Microsystems Slovakia, s.r.o. Drienova 3, 821 01 Bratislava, Slovak Republic
Re: Zilog 8530 maxspeed?
> 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 [EMAIL PROTECTED]
Zilog 8530 maxspeed?
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? Thank you very much for your input. -- Andrej Misik - Sun Enterprise Services System Engineer email: [EMAIL PROTECTED] tel: +421 7 43429485, fax: +421 7 43429486, mobile: +421 903 406075 Sun Microsystems Slovakia, s.r.o. Drienova 3, 821 01 Bratislava, Slovak Republic
