Twister 1200, Bitrates

 

• Knowledge of this table is usefull if there is trouble when trying to communicate between different interfaces. If you enter a special bitrate at a terminal application (or something else) the nearest possible bitrate will be choosen. These could be different rates!
• The table is based on a generic formula, which is the same for all devices using the 16Cx50 family UARTs. They require a clock which is 16 times higher than the bitrate.
• The max. bitrate at Twister (22.1184 Mhz X-TAL) would be 1,382,400 BPS which is too much for the transceiver chip used. An additional register controls a clock divider which supports 16 bit natural numbers (0..65535).
• Using this calculation there are natural values and fractional values for the bitrate. The fractional values were replaced with a bar on some entries.
• If the fractional number was close enough to an "important" value the deviation from that value was entered.
• Attention: Modems and ISDN-TAs usually support "autobaud". This is not supported at higher rates. For Zyxel-OMNI you'll have to do a manual selection at that device if you like to go beyond 460,800 BPS.
• Any rate lower than 9600 has got a continiously decreasing deviation of 0.7%.

Divider Bitrate (kBPS) 0 not supported 1 not supported 2 691.200 3 460.800 4 345.600 5 276.480 6 230.400 7 -- 8 172.800 9 153.600 10 138.240 11 -- 12 115.200 13 -- 14 100.000 (1.3%) deviation 15 92.160 16 86.400 17 -- 18 76.800 19 --

Divider Bitrate (kBPS) 20 69.120 21 -- 22 64.000 (1.8% deviation) 23 -- 24 57.600 25 55.296 26 -- 27 51.200 28 -- 29 48.000 (0.7% deviation) 30 46.080 31 -- 32 43.200 33 -- 34 -- 35 -- 36 38.400 37 -- 38 -- 39 --

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Divider Bitrate (kBPS) 40 34.560 41 33.600 (0.4% deviation) 42 -- 43 32.400 (0.8% deviation) 44 -- 45 30.720 46 -- 47 -- 48 28.800 49 -- 50 27.648 51 -- 52 -- 53 -- 54 25.600 55 -- 56 -- 57 -- 58 -- 59 --

Divider Bitrate (kBPS) 60 23.040 64 21.600 72 19.200 75 18.432 80 17.280 82 16.800 (0.3% deviation) 90 15.360 96 14.400 144 9.600 ... ...